Is this preterm labor ?!

Jesenia

Yesterday I went to the hospital they found I was having contractions 2 to 3 minutes apart and dilated 1 cm. I called today ( a bit embarrassed cuz I dont want to be a pain or to eager) cuz I had about 10 contraction in an hour and I think I just lost my mucus plug. Should I be concerned is this a reason to go to the hospital again? Cuz why did they discharge me if the contractions never spaced out but I didnt dilated any further.

Update: the day I went to the hospital was the 21 the 22 I kept having the same symptoms. I was feeling a bit better the rest of the days but today I think I have the contractions again cuz for hours my stomach has been hard and for the past 2 days I've been taking tums cuz I've gotten so nauseous & headaches ☹