Possible pregnancy?

I had vaginal sex 7 weeks ago without a condom. HOWEVER, he only went in for like 4 min and got out. So no he didn’t finish inside me.

Other than that my Bf and I stick to anal bc we both enjoy it more. We always use condoms and I’m on birth control. But I missed my period this month and have no symptoms of pregnancy other than missed period and light spotting the last week of April. I feel fine.

But what are the chances of pregnancy?