has anyone gotten pregnant from pre cum?

Usually my bf will pre cum before sex, like during foreplay. The other day, it had been almost a month since we've had sex (busy with work and other stress) and while we were having sex he pulled out and felt the tip of his penis and looked at my vagina for a few seconds, then continued. After we were done he told me he pre came inside me, which isn't unusual but he felt it enough to pull out and I assume try to see if it was actually cum? I just wanna see if any women here have FOR SURE gotten pregnant this way. We're both adults and would welcome a baby, so now I can't stop thinking about it. My period is due in 9 days, this happened during my "green" week. We've been having sex this way for 3 years without getting pregnant.