progesterone injections

analogy

I am currently 6 wk 2 days and had to start getting progesterone injections three times a wk til 12 wks.. My level was only a 6.2, they did do an ultrasound at 5wks 6 days n saw a 107 BPM heartbeat. I have miscarried once before my Daughter n was just wondering if anyone else has went thru this and not miscarried from it? I am so worried.