What the OB/GYN would normally do for too frequent periods is put you on the pill. When I had my daughter, they weren't sure that birth control was copacetic with breast feeding so we did the withdrawal method for a year, which I hated because my periods were heavy and lasted at least 7 days, horrible cramps, ew.
By the time I had my second child there had been enough studies that my OB/GYN put me back on the pill. Breastfeeding went fine and I didn't suffer, and I didn't leave myself vulnerable to another little bundle of joy.
If you are one of those folks that cannot tolerate the pill you are just going to have to suffer through it but one thing you might try is staying off your feet more if you are running around with the little ones. I know I bled worse after the deliveries because I was doing too much, I would think that could possibly affect your cycle as well.