I’m so confused

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Okay so I don’t want hateful comments so if you are going to be rude please don’t comment . I had unprotected sex on the 30 of December I had my period on the 25th i was off my period and on the 5th day I had brownish discharge come out for only that day I just though it could have been my period just wrapping up but it didn’t happen until 6days after I have been feeling super nauseous and I have major headaches I frequently use the bathroom at least 15 times a day no exaggeration. I’m constipated recently my dog has been coming up to me sniffing my stomach growling at me and whining sniffing my boobs and my crotch trying to hump me he would come up to me and whine and lick my stomach he’s been fooling me around the house as well I have been having great amount of pressure on my stomach my boobs are super sensitive and I have a burning sensation and when I pee it’s white discharge that comes out I was supposed to start my period the 16th of January it didn’t come I know it’s only been one day and I am waiting on my period but I find this very odd . Could I possibly be pregnant ? Or is it all in my head I know some of these symptoms are in tune with a uti as well I need help !! Please give your opinions