Prodromal labor?

I am due June 7th and started contractions around 8pm last night they were about 8 mins apart and would last 30-40 seconds.  By 2 am they got stronger and closer together 4 mins apart for 40-60 seconds.  We headed in to be checked, I was not progressing so they had me walk.  A few hours later I was still having the same contractions and they checked me again and no progress so we got sent home with what they called prodromal labor.  I am still contracting but not nearly as much or as strong but has anyone else experienced this?  How long before actual labor kicked in?  They said this could happen for days😭