can't stop stressing about it. help please. no rude comments. I know sex education. I'm just making no sense right now because my symptoms are freaking me out.

Hi guys. 3 weeks ago I have started for the first time in my life to get intimate with someone. That someone being my boyfriend. We dry humped and stuff like that. But i'm scared that I might be pregnant. I am a virgin. I haven't been penetrated or touched by his penis without my underwear on. Still the internet says that there is a possibility for u to get pregnant and virgin, if he cums or pre-cums on your underwear...? I have no idea how true is this. Or just a myth. I've been so stressed and I CAN'T STOP FREAKING OUT SINCE HE LEFT THE CITY 3 weeks ago. I immediately started to feel sick etc. 
I have no clue if he pre-cummed on my underwear. He says that he didn't. But I was really really wet. I mean I've never been that wet my entire life. 
THE THING IS. My menstruation...I hope it was my menstruation, came 3 days ago. I woke up so happy that It came. And then it stopped. I searched the interned why it stopped and then appeared again very light. The answers with implantation bleeding freaked me even more. Now it should've been the 4th day of my menstruation but it stopped. So it lasted 3 freakin days. I am crying. I don't wanna take a test because I am scared it might be positive. My family are going to kill me, they are very strict. They barely let me out 2 hours a day. Please help me, is a pregnancy possible...?
My bleeding was light. But then it had clots and got red. Again dark brown, pink, red with clots. And then just clots and stopped.
Help me. I am so scared...