Are hot baths safe during pregnancy?

I'm 37wks pregnant, and although I knew the risks of saunas and steam baths, I've taken hot baths several times throughout my pregnancy, and am now a little worried. I've only done this when I visit my parents(our bathtub doesn't have a stopper), and I think I've only had hot baths 5 or 6 times my entire pregnancy, but never for more than 10minutes, and I don't think I was ever overheated; the tub was so small that I really couldn't submerge much more than my legs and , the water never went over my belly.