Hi sillywmama sorry to hear you're feeling stressed, maybe don't tell exP any of your plans so he can't try and muscle in on them? I agree with you, I'd certainly not want him coming to playgroup, just stay really calm and explain that when you have spoken to your lawyer and planned access/shared parenting/however you're going about it, he will have his access set in stone and can start from there. Would make things easier on you, and keep it mature and rational, when you just want to kick him in the head 
I am trying so hard to focus on the good things, like being a single parent is twice (or maybe four times?!) as hard, BUT you are the one they turn to usually, you get to reap the rewards of that hard work, all without some loser dragging you down. It does help to see that you would do the same as I am, I think every reply has said the same thing too! eg. get rid of him and enjoy life.
But seeing as he's still here, I admit I've wavered, thought it's nice to have him come home and take over a bit with the DDs, he's being super helpful becasue he knows hes utterly in the wrong though so it's all bullshit really.
In fact I might look right now at property-to-let websites in the area and see what's available and what he can afford, to spur me on a bit. Dragging it out like this is incredibly stressful!
How far gone are you in your pregnancy? Im 30wks today, not long now, eeek 