Any experience taking progesterone?

Hey guys! So, I’ve had two miscarriages in the past five months. In November, my doctor started me on progesterone. I started taking it 16 dpo and then when my period was supposed to come, I took some pregnancy tests. I saw faint lines on pretty much all of them (but they could’ve been EVAP lines). So I was surprised when my blood-work came back negative on Monday. I haven’t taken the progesterone since Sunday night, but still no cycle? I’ve had mild cramps and even had brown spotting about a week ago. Anyone have experienced with this? I feel like flo is going to come with a vengeance! 😩