I resumed running and Pilates around 5 weeks but took it slow. My body seemed to handle it well (no bleeding or anything) so I ran a few more times that week. Got the official ok from my OB shortly thereafter. I was not ready for HIIT at that point though - that would've been too much for me. As it was, I would get weird pains in my pelvic area if I ran too hard or was too aggressive with leg exercises. They went away for good after a few months so I think it was just my body slowly getting back to normal. FTR, I ran a marathon right before getting pregnant and continued to run until my third trimester, along with doing prenatal yoga and lifting weights, so I was pretty active before and during pregnancy. It still took some time to really get back to my pre-baby level. Just give it a try now if you're feeling good and see how you feel during the workout and after, then adjust accordingly. GL!