Can you get pregnant with mirena iud if boyfriend cums inside of me ALOTTT everytime we have sex?

Can I get Get pregnant with the MIRENA IUD? 
Everytime my boyfriend and I have sex he cums inside of me a lott. I've taken two home pregnancy test and both negative. I been feeling really weird lately. Headache, dizziness, bloated, cramps, spotting(once 2 days ago), tired, migraines, frequently urination. I need answers.