External fetal monitors do not necessarily measure the strength of contractions. Internal monitors do that. They measure frequency and duration. That being said if you aren't writhing in the bed you aren't in labor. Nurses can usually tell be your demeanor alone if you are dilating or not.

They look for more consistency with the contractions or if your water has broken and so on.

they weren't getting high at all, but I asked them to check me because of the swelling and the dramatic change in her not moving at all today & they wouldn't. towards the end right before they had me leave I hit two 60 contractions when the highest number on the monitor were 100. & then the rest were stead 30/45.

They get like that cause ur not in labor they going to send u home they love doing that lol