Feeling nervous

okay so I got my period the 18th of September it lasted six days and it ended on the 23th. on the 28th when I went to the bathroom and wiped I had some pink possibly brown but it looked pinkish. like only one time when I wiped. I had a 30 day cycle this app tells me I'm supposed to ovulate on the 4th another app tells me I already ovulated I'm so confused on whether or not I ovulated or not when I Googled it it told me that I was supposed to ovulate around the same time that this app told me. I'm trying not to think about it even though me and my husband are trying to conceive but it's hard to not think about it. I almost feel like I'm going to be out this month trying not to be negative about it but it was just a weird experience for me to get that one time whatever you want to call it period thing. do you think I'm just overthinking it. here is a picture of what it look like. I don't recall that ever happening to me before I have had children before and don't remember ever getting implantation bleeding. someone said I could be old blood but I don't understand why old blood would take six days for it to come out but okay