Pregnant??

Okay so when I was 15 I got pregnant and had an abortion (not my choice) and ever since I've been on birth control. The first year I was on the pill then I switched to nexplanon which I've had in my arm for a year. At first I wasn't getting a period then I would get my period every few months and then these recently I've be n getting my period regularly so I was expecting to get my period. I've been really careful and I've also been using condoms when I have sex. I'm now 18 and I started talking to this guy and we've only had sex twice but the last time with was like almost a month ago. Well after we were done I started feeling something coming out of me and so I touched it and it was nut but I thought It was mine but I didn't orgasm so that was really weird to me. Then I'm feeling around and the end of the condom ripped off I guess and it was on my finger so I put two and two together and I was like this is his nut that was inside of the condom now its inside of me. But it was no big deal at the time because I was like ok I'm on birth control I should be okay. Until now. I'm 20 days late on my period. I haven't had any pregnancy symptoms like at all but when I was pregnant before I was peeing a lot and sleeping sooo much so I think I would know how it feels but who knows this time it could be different and I could just not have any symptoms. I also took a test like two weeks ago and it came out negative but I said I would take another one just to make sure in a few weeks so I'm gonna take one again soon. Im just scared. It just sucks because I thought that I was being really responsible and careful and now this is just nerve racking. Someone help me please :)