So normally with my iud my period is on time and very heavy and lasts about 4-5 days.. this time my period was a week late and it only lasted one day and I've taken 2 hpt both negative.. my stomach feels hard and I've had what feels like menstrual cramps for a month and a half now. What's going on!?

There's really no way for us to even guess what's going on.

You could be pregnant and it was too early to test.

There could be something wrong with your IUD.

It could be something totally unrelated.

If you're concerned than see your doctor.