Help.

Okay so I've have the paragurd IUD since last June, I haven't had any cramps or spotting between periods, they have also been very regular. But this month has been completely different. cramps on and off since my last period. Aunt flow is supposed to be here in 3 days, I have been spotting and cramps have increased the last few days. I have also been nauseous for the last 4 days... could these be possible pregnancy symptoms? I have 2 other LO's (6 and 2) I wasn't on any kind of birth control then though.