Effaced/Dilated but cervix ok on u/s?

I am 32 weeks preg and been dealing with PTL cont for 2 months. I went in on Wed with blood and I was still closed, tight, thick. Thursday had bloody show all day (mucous with bright red/brown blood). Went to do today, Fri. He checked and I was 1-2 cm dilated and 70-80% effaced. Went to L&D and the internal u/s showed that my cervix was still long and looked good. What does that mean? Seems like a contradiction. They are making me come back tom. for FFN (due to the bleeding I need to wait 24 hours) and then see results before starting steriod injections. Anyone else seen or heard a story like this? I am just confused.