time them for at lease 30mins. if they are constant then I will suggest you to go in. (l&d is picky, I was having contractions every 2-3mins and they tried to send me home until my water broker getting dressed)
if u lose your mucus plug, its mucusy (like a big blog of snot) or you can it can be a "bloody show" where you lose your plug and blood be with it. that's normal for blood to come out with your mucus plug. now your contractions, time them.. If they constant for 3-5mins go to l&d..