When to go in

I'm 38 weeks & I had contractions start at 3:50pm earlier today. I went about my business and they got stronger and closer together. Well I called L&D. My midwife said to relax, take a bath & if that doesn't help you're in early labor and to give a call when they get stronger. Well I did as she said and they never went away. So to speed things along my husband and I ended up having sex. Now the contractions are strong and close. My midwife told me I didn't have to time my contractions if I didn't want to so I haven't. I'm just curious as to how long I should wait to call her?