Help? thank you😊

I often flunctuate in weight. I stay at around 112-115 most of the time. Lately I've noticed a number on the scale I'm not used too: 118. I checked my period tracking app before I switched to this one about a week ago and it said I was 5 days late. I took a test and I got a negative. I waited until today to take another one and to me it looks negative! I'm so confused because I'm now 12 days late, my breasts have grown and are super sore, I have a lot of acne I generally don't have, I feel super super tired, and I'm nauseated constantly. My mood is out of control as well. I never have PMS symptoms either. The only thing that comes along with AF with me is cramps. The first day of my last period was August 19th. It ended the 25th and I had intercorse  several times between then and now. My period has never been completely regular so could it just be too early? Also, this was not FMU. 

 Thanks for any help! 😊