I didn't have this problem, but I read somewhere along the line that it's the fluid you were retaining making it's exit. It takes days/weeks to get rid of all that extra liquid we were carrying around in all of our swollen parts while pregnant
I'm sure some of it has to do with our lady part muscles being weakened so we feel the need to urinate frequently to keep it from leaking. Kegals! And squats! Exercise what's between those thighs. Lol
I'm peeing a lot but I love it...I think the thing I liked the least about being pregnant was feeling the need to pee constantly but then sitting down and only being able to go a little. Fully emptying my bladder after delivery was fully awesome for me. After my epidural and catheter I actually told DH I loved the catheter bc it was the first time in MONTHS that I didn't feel like I had to pee. He was like "I don't think you mean that." Haha.
Re: Anyone peeing more after giving birth than while pregnant?