what do contractions feel like? i know what braxton hicks feel like n its not those i believe. its…

what do contractions feel like? i know what braxton hicks feel like n its not those i believe. its like braxton hicks (the really tight feelings) but mixed with period like cramps n some r more painful then others n when it happens it doesnt last long but i cant move or it gets worse. they arent one after another either maybe 3 in the last 45-60 min. im 35 weeks today.