Hello, I have had the Mirena IUD in for about a year now with no issues. I also am also very sexually active with my boyfriend, and since we did not believe in the possibility of pregnancy with mirena, he has been ejaculating inside of me. Recently, about a week and a few days ago, my breasts have been itchy, my nipples have been tender to the touch, pelvic pain, and I've been more emotional. I read online that sometimes the mirena causes pregnancy symptoms, but this has never happened to me before since I've had it. Ive also been slightly nauseated in the morning and sometimes at night. I don't have any food adversions but I have been getting a lot hungrier than usual. My last menstrual cycle was about a month ago and I didn't experience any of these symptoms. I'm starting to get cramping in my lower abdomen, lower back and pelvic area as of today, as if my period was starting. I'm really confused as to what is going on.

Pregnancy is not common with an IUD, but it does happen, often due to the IUD slipping out of position. This could be due to a period about to start, even if you haven't had these symptoms before, but it could be pregnancy. Some women will have early signs of pregnancy, even before they miss a period. This will depend on when they ovulate and when implantation occurs.

See what happens when you expect your period. If no period, or it seems different from the norm, try a pregnancy test.

Any time you have sex, even if you're using one or more forms of birth control, pregnancy is possible. There are many women on this site alone that got pregnant using Mirena.

Have you tried a pregnancy test using first morning urine?

I did buy a pregnancy test that afternoon. At first I thought it didn't show anything other than negative but when I looked closer I think there was a really really faint positive. I was going to wait a few more days or maybe a week and try it again in the morning. When I was outside today, I started to get a little nauseated but I wasn't sure if it was from the heat or something else. Is it really that common to get pregnant from the mirena?

It's not common or uncommon, not in the way you're thinking. There's no form of birth control that's 100%, so any type you use, pregnancy is possible, and does happen. There are woman on this site that used 3 different forms of birth control, all correctly, and still got pregnant, some more than once. It happens all the time.

Update:
I've been having some minor cramps the past few days and have been feeling queasy. As I was using the bathroom this morning, I noticed some very light pink blood on the toilet paper and in the toilet. My periods are definitely not this color, they are usually either a bright red or a little darker. I also experienced a few cramps but then they went away after a couple of minutes. Should I be worried?