I just talked to the teacher in my childbirth class. Her advice is to only go when contractions are 4-5 minutes apart, lasting one minute and continue straight for an hour. (she called it the 4-1-1 method for ease of remembering).
Funnily enough she also said to take tylenol and take a bath in order to relax because you are going to need the rest for later! She said if it's true labor, a bath won't slow it down or stop it, and the medicine will make it easier to relax. Even if you fall asleep, labor will wake you up with plenty of time.
She said if you can talk at all through a contraction they might not be strong enough to come in. Also, first babies tend to take longer and a women can be contracting for a long time before they are in active labor.
Sorry if it's not much help! it's my first baby too!