Hun, when you are in in the late stages of pregnancy, your body produces a hormone called relaxin which makes everything loose so that your pelvis can open up etc. This makes you extra flexible and it is very easy to do damage to muscles, tendons etc. The relaxin is still in high levels for 6 weeks or so after the birth, and without a pg belly to stop you overdoing it, it is very, very easy to do long term damage. Also, your pelvic floor and core muscles have been very strained and need to be eased back into use very gently. You can start to do very gentle pelvic floor exercises while lying down in the beginning, but it is good advice to wait until 6 weeks before doing anything more strenuous. You have just given birth hun - give yourself some time