Low progesterone- baby survives ??

Hello All! Can anyone help me? I had a bit of red spotting after pooping at 5 weeks 1 day, went into the doctor at 5 weeks 3 days (only one other time after pooping again) the doctor found a sac (said it looked a tad small) and ran my levels. The next day, at 5 weeks 4 days he called and said my HCG was 1,700 but my progesterone was 5.4 and I would more than likely miscarry. Later that day, (yesterday) I bled for the first time without any straining. I thought this is it- but it stopped again. No more blood. Only stringy like brownish red sometimes when I wipe...it’s almost not happening at all. I’m sooo confused! Has anyone had a similar story and had their baby make it???