4 weeks - postpartum checkup

My labor with my second child was only 1.5hrs and I only pushed for 4 minutes before my daughter was born. My postpartum experience this time around was very different from my first as I experienced no vaginal pains or soreness past the first day, no stitches or tears and right after delivery, the doctor said my vagina looked “perfect” haha (I made sure she repeated for my husband to hear 💃🏼), and I only bled for about 2 weeks, though not heavily. It was mostly just spotting on and off. With all that, I scheduled my postpartum checkup at 4 weeks as I am so ready to do light exercises but want approval first.

My question is, has anyone been approved for exercise & sex as early as 4 weeks? Will my uterus be back to its normal shape? I’m in no rush for sex as I’m just so exhausted and my sex drive is low right now, but I would like to do more than just walk if I can. Let me know your experiences & what your doctors have said if you went to your checkup before 6 weeks!