Pregnancy help

So my bf and I had sex a few days ago (2 to be exact) and I’m just a little worried about pregnancy. I’ve always been a worry type of person so it’s not unnatural and I like to think I know a lot about my body and the female body and sex but there are somethings I need help with so please if you have time answer these questions below

1. When does a woman normally ovulate

2. What are some signs you’re ovulating

3. If I’m on the IUD should I always be as worried as I am?

4. There has to be semen involved for pregnancy

5. Any weird fact you know that will help and keep in mind when I have sex again.

And yes we used a condom but we took it off midway (eee) and continued. He didn’t cum because we stopped and he doesn’t really have Precum (weird Ik...)