Need advice

so I’m a 32 year old women married for almost 7 years and I have a very strong feeling that my husband is cheating with one of his co-workers but I need help getting to the bottom of this. He denies it. I’m really hoping I’m just over thinking and not true. But it’s a feeling I can’t shake and don’t know why I feel like he is. One of the reasons why I think he is is bcs he’s changed so much with me and it’s all within the two going on 3 years he switched to this new company (job) he’s gotten so disrespectful not as sweet and loving anymore doesn’t text me threw out the day like he use to always makes up excuses to spend time with me. Well anyways my suspension started one day that I took my girls to take a picture with Santa. This girl I had never ever meet in my life was staring at me and my daughters you know that feeling you get when someone is just staring at you, anyway I didn’t think nothing of it but I noticed she kept walking around wanting to see us this was at a local plant store. She was with another women and I can see her from the corner of my eye saying something and looking at us. I thought that was really strange and left me thinking why was she staring almost like she knew me or something. Anyway one day I was scrolling threw Facebook and came across this familiar face so I went and did a little snooping came to find out she works with my husband. Huh funny right. Anyway fast forward to Valentine’s Day. My husband who works every day except Saturday & Sunday started working every Saturday too. Odd bcs he never use to he says he has so much work. and I stay home with our girls bcs we had agreed on it since child care is so expensive and only one of 3 girls goes to school. Anyway on Valentine’s Day he worked so late that he got home like at 8pm with flowers of course but seemed off distant. Anyway later that night I grew even more suspicious bcs I was on Facebook that day and I know I shouldn’t of snooped on the girls Facebook but for some reason I did again & I don’t know I just had this weird feeling to do it. Anyway I went and I saw her pictures and she had posted a video of flowers she got from someone anonymously and the flowers looked just like mine except mine were 30 roses hers were 50 roses. They had a note that had her name on it but it was from the same flower shop my husband gets my flowers with her name writen on and it I swear I must be crazy for thinking this but I swear I got like this crazy weird feeling & it had her name writen on It & it looked like my husbands sloppy writing. And in the video she said omg 50 roses everyone was asking her who were they from and she just wouldn’t say. So I’m over here tripping thinking like damn could it be. Where was he this whole time he usually gets off work at 6:30. I was just loosing it. I must be crazy so I was like whatever I’m dumb for even thinking that. I let it go. But one day out of curiosity I asked him I said do you know a girl names yesica he looked shooked and said no why? I said oh really you don’t that’s funny are you sure? He said yes why? I said bcs I have a feeling you do! I said really there’s no jesica that works with you?! So he finally said oh yea there is but her name is yesica with a y I said oh so why did you say there wasn’t? He said bcs I didn’t want you to start accusing me. Really accusing. So I said what does she do there like her job description so he said oh she works in this blah blah in the lines so I said huh that’s funny that you know exactly what yesica I’m talking about bcs working in a big place like that you would think there is more girls with that name it’s a common name. So I said how did you automatically knew I was talking about that spacific girl. So he said that was the only yesica there. bull crap I don’t believe that. I know for a fact there is another jesica there with a j but still I know bcs one of the supervisors name is Jessica I don’t know how she spells but yesica Jessica sounds the same to me so for him to know exactly what yesica I was talking about left me more confused. I don’t know If I’m over reacting but it’s just fishy to me. He works like everyday doesn’t text me all day when I call him he doesn’t really answer always has an excuse or is so damn busy. All he cares about is work. I mean I understand he has a big part with with company and thanks to him we can afford the life style we have. But me and my daughters are last for everything so what kind of life is that. He says he works for us. Yes but at the end of the day we would rather have nothing but have him be a present dad and husband. Anyway it’s doesn’t stop there. My husband is a supervisor for this fruit company and I understand he has a lot of work and has to deal wit girls with everyone all the ppl all day. And I’m not against it but when you are in a position like his and have a certain amount of power and if he’s giving this girl easy jobs and letting her hang out in the office when clearly that’s not her job description then something is not right. Or am I just delusional. I also know for a fact that only supervisors are allowed in his office. Well this past Saturday he worked said he was only working half a day ended up working till 3 or 4 said they were only repacking fruit till like noon. so only the repack crew was going in. Well well I again out of curiosity went to that girls Facebook and guess what she posted pictures videos of her sitting in my husbands office taking selfies bragging about how easy her job is. Wow so am I missing something here or am I just crazy?! I asked him when he came home and said how was work? Small talk you know. Asked how repack went and if they got everything done for the day and he said yes. So I just decided to ask him straight up I was upset I said so none of the other co-workers had to come in he said no. I said that’s funny bcs the girl that works in this department went in huh why is that? He said oh bcs she this and that and didn’t really know what to say I said so she just comes in to look pretty in you’re office. He looked surprised but then turns around and says I don’t know anything she had to come in this and that. I said why if she doesn’t work in repack and why is she in you’re office when only supervisors are allowed in there no one else. He said no she has to go up there and use the computer to do her paper works at times this and that. I think is all built crap and he thinks I’m dumb! Am I over reacting. So he got mad and took off. Didn’t want to give me explanations and said he doesn’t have to give details about work and all that. Wich is true but why get so defensive and acts like I’m the crazy one and it’s my fault. when clearly he’s not being honest. I need help I have a feeling something is going on and I need some evidence way to prove it or find out. I’m thinking of a tracking device just to find out once and for all. It’s killing me. He’s all of a sudden wanting to work out wakes ups early in the morning before work to work out. Like who does that?! I don’t know there’s so much. That I feel he is. One time he was working out and says look I think I’m getting stretch marks from working out. They looked nothing like stretch makes and looked like hickeys like by his boob area. Like really. So I waited a couple more days and said wow I thought you had stretch marks. He said oh it’s was probably bcs my shirt was too tight. Really. But I have no way of proving it. He says I’m crazy this and that. I just need help. I know I have to be independent and get a job first and I guess prepare myself for worst case senerio. But I just don’t want to keep living like this anymore I need to find out but don’t know how. Please any advise would be great thanks for listening.

**thanks ladies for hearing me out it’s been really hard and I’m going to be devastated if this turns out to be the truth but I do need to get to the bottom of this & get closure. I can’t take it anymore. Also for the women suggesting I go threw his phone he has a lock on it and won’t let me go threw it. Another red flag right?! Also I’m not on the bank accounts and don’t have access to the statements bcs I’m not on there. Is there any other advice? Seems like a tracking device is my only option right now. But don’t know where to get one or anything. Thanks again