Braxton hicks

Crystal
Hey mommies I have a couple of questions! 
So I'm 32 weeks tomorrow due August 9th
And today I've had about 3 Braxton hicks and I started to lose bits of my mucus plug also. 
How soon can I predict that I will be going into labor? And how soon can my ob start to check how much I've dialated? I have an appointment on Monday I will be asking but just seems so far from now.