Pregnant and sharp pains in vagina?

i am 29 weeks and 2 days pregnant with my 3rd child. you would think i could remember what this is, but nope! lol. it doesnt matter if i am sitting or standing, i will randomly get sharp breathtaking pains "deep" inside my vagina that goes as quickly as it comes on. i have tried googling it and on Baby Center site, it says its caused by the dlalting of cervix. which seemed to jar a past memory of this being true but still not sure. thing is, its way too early to be dilating. Anyone have an answer? Possibly from maybe what their docs have said? :) I also have braxton hicks contractions everyday. (info just in case they go hand in hand) thx in advance