Sensitive discussion; What do you think is going on?

Okay, this is very confusing for me so I apologize if this story is all over the place.

On 04/06 I got a pretty noticeable faint line, I kept an eye on it and tested to watch it since my period was due 04/07. I had been spotting/pink discharge for about 6 days(reason I tested). On 04/08 my pink discharge changed to a period red with very minimal clots and small tinges of cramp like pain in my pelvic area. On 04/09 I went to the ER because I was nervous about the bleeding. I was bleeding  not quite as much as a period but close. The ER tested my blood with a Quant Beta and my results were 4 miu/mL, so the Dr. suggested I come back in two days for another blood test to see if they are rising or going down. Today on 04/10 my bleeding stopped mid day completely and keep in mind I haven’t had ANY major clots or tissue bigger than maybe the end of a Q-Tip here and there. Today I’ve been sitting in bed all in my head confused and upset because I’m unsure if I’m having a MC, chemical or if there is some chance I’m pregnant. I have two previous live pregnancy’s and never had a MC or chemical that I know of.

And also since I keep seeing people mentioning this I have a “resting HCG level” of 0.2-0.4 every beta I’ve ever had not pregnant, not sure if that matters.(I get blood work a lot due to a medical condition).