IUD - HELP

Hi everyone! I just had a quick question. So my doctor said that the iud would be effective immediately after insertion (if you get it during your period)... So my husband and I decided to have sex the next week (I let him finish inside), i wasnt feeling any pain so i thought it would be ok. Its only been two week since my insertion, Maybe its just my anxiety but im worried...what if im pregnant? im spotting still, still a little crampy, and my breast are a bit tender.. Has this happened to anyone? i am just freaking out?