Plz help, really painful stomach

Jacqueline • Had 3mc's and 2 mmc's, finally had our rainbow baby 14 September 2016, now trying again for number2
I hope someone can help me, for the past 3 months or so my lower part of my stomach is really painful, feels like a huge bruise, also my back aches, is this normal, and also I hurt my right side of my stomach last night while trying to get out of bed, it's more painful now than its been before, I'm seeing my doc tomorrow but I'm just so nervous. I'm 21w4d. Baby is still laying very low, she likes making my bladder her jumping castle lol, can that contribute to the pain? I really hope it's nothing, would just like to ease my nerves till tomorrow.