Worried. Advice?

So... Yeah. I'm youngish. More mentally than physically. I'm not ready for a child. Well, my boyfriend and I are both virgins. We were having a bit of fun and experimenting. Long story short and to spare the details...

We were spooning. Our pants were down. There was quite a bit of grinding. And he ended up putting the head in my ass. It was an experimental thing. It didn't last more than 5 minutes. But what I'm worried about is precum. There wasn't much but it was definitely there.

I'm on birth control. So, I shouldn't be worried but I had forgotten to take my pill the day before. I had completely forgotten until he asked if there was a chance I could get pregnant from what we did. I got worried. I doubled up on that day's pill and called it good. It was the most I could do. Any advice? I probably shouldn't be worried but is there anything I can do to just reassure myself?

Please be helpful and supportive. I'm worried. Not begging for attention. Or anything like that. Every time I've posted on here I've gotten rude comments that tear me down because of MY choices and MY concerns. So, if you're going to be rude and ridicule me, I ask you to not leave a response. Thanks!