Early labor?

So, I woke up this morning because I was having pretty painful contractions at about 7am. I lost my mucus plug last week, and this morning I started spotting along with the contractions. So they started being about 3-5 minutes apart, and my husband took me to labor and delivery because they told us to come when they were that close together. Long story short, we were sent home after a few hours because I wasn't dilating more, and it have been losing large pieces of blood and mucus ever since I got home and my contractions are still painful and about 4 minutes apart. I feel like they aren't taking me seriously, and I don't know when I should go in now. I'm at my due date and my baby was measuring 40 weeks 3 weeks ago. What should I do?