Sex help

I had unprotected sex on the 8th.

I was riding him for about 5 mins then I gave him oral sex until be cummed

The tip of his dick when he was getting aroused was wet, is that pre cum? But I thought you pre cam a bit before actually cumming.

My period days change. I haven't had sex in over a year. Untill I did on the 8th.

That is why I was on no form of bc.

I'm just really worried. I apparently was supposed to get my period but it also changes

Once I got it on the 31st then 21st then 24 etc etc

Just need some advice, extremely worried.

Thank you