Uterus pain

Hey everyone, I took a frer on Monday ( it’s now Friday) and got a vvvvvfl. I’m too nervous to test again until a few more days. Today I got cramping almost like period is coming on but then a few mins later I got what felt like stabbing pains, almost like a tightening, and pressure in my uterus. I have a low pain tolerance but this was quite painful. It was there for a few mins and then gone again. Any ideas?