What would you think?

Sooo... got my “period” this month. Usually it’s 4-5 days long two days of regular bleeding, I usually have to use super tampons for one/two days and then regular to light for two days. It was lighter than it was last month. Never went through a regular tampon. The day before my period I had a neg. test. Monday comes, period is super light with some red and brown blood. I’ve had a lot of brown blood mixed in with this period. For shits and giggles I took a test yesterday because my boobs are killing me and I started getting these sharp pinges of pain in my uterus and my period was just weird. My breasts never hurt with my periods. So the test was super super super faint ... I had figured maybe another chemical pregnancy? Today my breasts hurt again and more sharp pains in my uterus. My period lasted all of two days, not heavy at all but it did have bright red blood with it. I took another test this am - slightly darker than yesterday. I actually have an ultrasound scheduled Tuesday for recurrent chemical pregnancies- checking my uterus and ovaries to make sure everything is good. This would be my third child. I’m just trying to figure out if it’s another chemical pregnancy or is it possible that I could possibly be pregnant.