Pregnancy risk?

I’ve been tracking my periods, but since coming off birth control about three months ago they have been irregular. I had unprotected sex (he didn’t cum in me, but there was definitely pre-cum) two weeks ago. I thought I was in the clear because my projected ovulation day wasn’t for another week. I’ve since been experiencing symptoms I would normally attribute to my period...but it isn’t due for a week. So, my questions are these:

Is it possible I ovulated early?

Is it possible to get pregnant off pre cum?

When should i test (if at all)?

Am i stressing over nothing?

TIA !!