IUD & possibly pregnant????

I got my IUD in mid June and for the last month and a half my boyfriend and I have had unprotected sex once a week and he finished in me every time. Over the last week/ week and a half I've felt a little bloated, I've had very light spotting, light cramping, and I've been nauseous every once in a while. I'm pretty sure the spotting wouldn't be my period since my period stopped overtime from the IUD. Could I be pregnant or is it all in my head?