Pregnancy Scare

How many moms got pregnant the very first time they had intercourse unprotected i just had the iud and it came out me and my bf at the time had intercourse but i had my period with all the pregnancy symptoms not sure if im pregnant but i been peeing a lot i been lightheaded and my period barely came on the first day then it would get heavier then lighter this is all frustrating any advice other then talking to a dr or taking a test i just need to know im not the only one who experienced this?? Thank You