Could I be pregnant.

Hello everyone, I'm Ayana, I'm new here. I'm desperately in need of some advice. I suspect I may be pregnant, only thing is, I have an IUD inserted. I haven't taken a test because I'm not sure if it's just the birth control causing my body to react or if I'm really pregnant. I've had the IUD for a year, and no problem with it until now. The first time my partner and I were intimate was sometime in April, (not sure of the exact date) later that same day, a few hours later, I got my period. After my period ended, (not sure of the exact date) we were intimate again, a few times, no condom, cause I was on the IUD. I still am. I believe the last time we were intimate was sometime in May, again I'm not sure of the date. A few days later, I began to bleed, I thought it was the start of my period, but it was super light and only lasted a few days. Other than that,no bleeding the remainder of that month...in June there was no sex at all, but my period took forever to come, and when I bled, again it was light && short. This month, I started to bleed a few days before the first of July, again, short and light, nothing since... I have cramps every now and then, I feel dizzy at times, always tired, hungry, and frequent urination, and back pain. No morning sickness, but nauseated at times, what is going on??? Please help. Should I see a doctor or is it just my birth control causing symptoms...??