becoming a surrogate

I would love to become a surrogate mother in the future (maybe 5 or so years) My husband supports me. I know to become on, you cannot have had any pre term labor before 36 weeks. 
My question is (if anyone knows) is this for all cases? 
We recently delivered a baby at 24 weeks due to problems with the placenta. It was not because of my medical history, it sometimes just happens and usually doesnt happen again. It is my dream to do this so im heartbroken to think that this could disqualify me