What the fuck?

Miranda
Alright ladies help me out. Am I crazy?
So I had what I think was my period. However it was a day shorter than normal since I had my IUD removed. It was also super dark and fairly light. That was the fifth of this month.
Ever since then I'm super weepy, gassy and have had a thick but creamy white discharge. I'm not due for another paid until the 3rd of next month and my periods are pretty regular.
I took a pregnancy test a couple days ago just to be safe and it said negative. However I also have had sharp pain in my uterus right by my hips for the last few days and feel slight flutters in my uterus as well.
Could the test be wrong?