Late Period

My period is 3 days late right now and I have been having light cramps and my breasts are tender. Typically my cycle is 25 days.

I am not on birth control, but me and my bf have had unprotected sex a few times (he pulled out each time). I know there is a possibility of being pregnant with pre cum.

I’m starting to get worried as I am not ready to have a baby yet.

I only started having sex two months ago, and I know that with some people having sex alters their periods.

Is this normal? Or should I be worried?