Pregnancy from precum

I'm really curious as to the % of getting pregnant from precum.

My boyfriend and I had unprotected sex for over a week, but we skipped most days in my fertile period. He never came inside me, although twice I did have to jump off quickly since he was struggling a lot by keeping in his load. He caught it in hi hand both times.

I'm just really curious, since this period in my life would be the absolute worst to get pregnant in.

Anyone think they can help a little?