Spotting after exercise anyone?

I'm 5 weeks pregnant (fourth pregnancy: missed miscarriage 2/26/16, dear daughter 12/8/16, missed miscarriage 11/30/17) and had some spotting after exercise this morning. This was the first time I've done a "hard" workout since probably September; I'm out of shape and it's been an emotional, hormonal few months. I felt a "gush" while I was on the treadmill and kind of assumed I just leaked a bit (sorry, TMI) but noticed a bit of pink blood in my undies and some pink blood when I wiped. it's been an hour since and there is now nothing on the toilet paper when I wipe, but I'm super paranoid. Although I never had spotting with the two MMC, I'm worried I'm going to miscarry again.

Has anyone else had spotting after exercise? I'm very overweight with PCOS and low progesterone (I take prometrium daily) so I'm hoping it was just from the strenuous activity.

Anxiously awaiting lab results for HCG and Progesterone levels 🤞🤞