pregnant after miscarriage???

I had my 2nd miscarriage in November. I was about 5 weeks. I started bleeding around the 22nd of November and on the 28th I had a u/s and they said I had passed everything. A few days ago I noticed I had some cramping on my side and my boobs have been increasingly sore. So I took a pg test and it came back positive. I took a few more since then and it seems like the line is getting darker! They drs never did any blood work so I don't know if my levels went back to zero and this is a new pregnancy or if it's leftover hormone from the last. Any advice would be greatly appreciated!