You don't think it's bubs sitting up or pushing up into your rib cage? I know that sometimes my ribs/back aches because of that.

I have been in & out of hospital with high BP and was told to let them know of any sharp pains on the right hand side where you have described because of liver issues. Not sure whether that is just because my BP is high or just in general and I don't want to be the cause of you freaking out either! Maybe just ring your midwives to ease your mind! They really don't mind answering any questions!