(nsfw) How do I know if I'm losing too much blood?

Due to my recent struggles with getting a period on my own, I decided to get back on the birth control pill to regulate my cycle. I am only half way through my first pack of the pill but on Monday, I got my period. This is unlike any period I have ever experienced. It is very heavy and extremely painful. I have been unable to do my normal daily activities. To give an example of how heavy it has been, I have to wear a super tampon and a heavy flow pad, and it still leaks through within an hour. There are big clots also. I’m wondering if this is just due to the fact that it’s been 8 months since I have gotten a period. I’m making up for lost time? Getting rid of everything that was built up? I’m still taking the pill daily, but the bleeding hasn’t stopped or lightened. At what point should I call my doctor? I don’t want to jump the gun and call too soon. I have begged my dr to help me get a period for months and now that I finally got one, I don’t want to turn around and tell my dr “Please make it stop!” Any advice?