Sex and Braxton Hicks - or is it early labour?

[mimosatree]

36 + 5 with DC3.
Have been having long spells if BHs since 33 weeks but nothing like what I'm having today after "doing the deed" last night! I've been having the worst backache all day and the contractions are at times moderately painful, albeit irregular and don't seem to be progressing! My belly is so hard that I can hardly walk and I get the urge to wee whenever a contraction kicks in.
I'm so fed up with this and really wonder if something is shifting or not. Has anyone experienced the same and has it all fizzled out in the end? One thIng is for sure, he ain't getting anymore any time soon!!!

i have had this on and off for a couple of weeks with or with out sex i am 34wks. the bhs get painful enough for me to breath through them. its enough to give a girl the wrong impression but they have always fizzled out i am assuming that eventually they just wont and i will be in full blown labour but its not massive amounts of fun in the mean time.