Why am i feeling cramps from the day of ovulation until my period comes?!?

When I ovulate i get severe cramos on the side of tge ovulating ovary that lasts for three days then i get on and off cramps in my abdomen that lasts until i start my period. It is a nasty feeling that just makes me so uncomfortable and hibders me to workout and just makes me tired all day. I am 29 and have two children.