16 and scared

I'm sorry this is so long but please help me. So I'm 16 and obviously not very well educated on sex. I had sex about 2 months ago and we used a condom but before he came he pulled out, took off the condom and came around my vagina. He says that none got it but you never know. I got my period early that month and it was brown and light and had small clots.  My therapist said its probably just my period cycle changing but I looked online and it said that it could be implantation bleeding. It lasted 6 days and never filled up a regular size tampon. The next month I got it early and it was normal colored. It was super heavy, filling a super +  in about an hour, which is usually normal for me. I passed one clot which was biggish but not huge, but I never pass clots like that. That period lasted 5 days and was normal. While I was on that period I took a pregnancy test because my nerves were insane and it was making me nauseous. It was negative. I've read about people getting their periods and being pregnant but they had a positive pregnancy test. The whole 2 months I have been experiencing nausea and been having creamy, thick, white discharge. I've also been having cramps all the time and lower back pain, which I never have. None of my clothes are tight on me yet I have been working out and I've lost 15 lbs. Since I have never been skinny or muscular before I find it odd that my stomach is hard to the touch, but not all the time so I don't know if it's abs or if I'm pregnant. I feel like if my stomach looks pregnant but I really don't know. On this app I am 2 days late and on others I should be getting it the 30th. I can't take another test because my parents don't know anything. Do yall think I could be pregnant or do you think I'm just stressing and overreacting??