As long as your doctor tells you everything is good in that department you can do any position you want. Although they will tell you not to use toys during pregnancy due to bacteria and all that could hurt you or baby. Other than that as long as your cervix is staying closed, you are not bleeding and the position you are doing does not cause you pain you can have sex all day long if you want. With my first, a boy, I wanted it all the time. With my two girls not as much and with my 4th want it but am usually too tired by the end of the day. Get it when you can now cause after the baby comes you have to wait 6 weeks and then you will be so exhausted you wont even want to. Besides good exercise.. Have fun!!!
Ya...if it hurts avoid it but otherwise fair game.
No just only do the ones that's not hurting you.