No you won't hurt bubs.

After I had my first baby the physio in the hospital taught me about the correct postion/technique for pooing. Until then I had no idea there was such a thing lol.

Anyways this is it.....

Get a stool or basin or similar that you can put in front of the loo to put your feet on. The aim is to raise your feet so that your knees are higher than your hips (so you are in a more squat like position because that is the position that our bodies were designed to use - the throne loo has only been around for a couple of hundred years). You should then lean forward slightly (you can rest your hands on your knees) and make your mouth into an O. You should keep your back straight and not slump. Breath out and as you do so relax your muscles. Then push - you shouldn't push for more than a minute. If you do stop and breathe out and relax again.