i've had the mirena IUD since nov 2011, my periods stopped around the beginning of february, about 4 weeks ago i got a couple of really weird stabbing/sharp cramping pains, they only lasted 20-40 seconds at least. But now i feel sick, i have cravings for some foods, im always really tired, and my weight has gone up by 3/4 pounds, any chance i'm pregnant? so worried!