35 weeks and cramping all day long?

So the other day I had what I expect a contraction to feel like, it was a one off but painful and lasted about 30 seconds. Two days later and I have had period like cramps all day. I asked the mid wife who said the previous contraction was probably a Braxton hicks although the other Braxton hicks I have had are tightening and painless. She also ruled out slight period pain as the same thing. But this has been all day... just wondered if anyone has been experiencing the same thing?