vaginapagina | Started new HBC pack late

Hey lovely VPers! I have a question and I just can't seem to find the right combination of words in order to find an answer via google. I'm usually very strict about always using two forms of contraception, so I've never really had a pregnancy scare. And I think I might just be paranoid.

So the situation: I've been on TriNessa for forever. I had PIV sex on the 6th day of my placebo pack (last Thursday), which was also the third day of my 4-day withdrawal bleeding. My boyfriend was only in me for like 30 seconds max and then pulled out. (My nerves can't handle pulling out, I'm definitely an HBC + condoms girl.) But he came fairly quickly after, so now I'm freaking out thinking he might've gotten some inside me before he pulled out.

Now the kicker is, in my infinite stupidity, I forgot that I didn't have any refills for my HBC and because my doctors office was closed for the next 4 days (it was Thanksgiving weekend), I didn't get my prescription refilled until the following Wednesday. 5 days late! Gah!

I know that sperm can live in the system for a few days. So I suppose my question is what's the likelihood I got pregnant if I had sex during my withdrawal bleeding/my HBC placebo week and he pulled out, but I didn't start my next pack on time?

Actually I guess the real questions are how long does sperm really live inside of a person? Does a person start ovulating as soon as they are finished their pack or does it vary from person to person? What's the likelihood of getting pregnant during withdrawal bleeding? And is there a Birth Control for Dummies-type site?!

I'm more curious than worried, I've been oddly fascinated by birth control recently! Thanks in advance. :)