Help???

so at my 37 week appointment today my doctor checked my cervix and said that im 4cm and 50% effaced. She did a lot of sweeping around in there & I've been having terrible cramping all day since then. Even went to work tonight.

My question is..if im now experiencing the pain flare up consistently every 5 minutes with some tightness is this a real contraction or just cramping from her checking me? My doctor told me today to come in when contractions are 3 to 4 min apart for an hour or more. Not to look for water breaking since some womens dont break right away.

Ugh, needless to say I am stressed out about when to go in..please help :(