advice!

Okay sooooo! Me and my boyfriend been together for 4 years we have a 1 year old daughter I'm currently almost 30 weeks with our son. We were supposed to be moving into a house on the 1st of June but supposedly their not done with it and it'll be ready on the 12th the thing is how do I know if he's lying or not😒 and now we have to move out of our apartment cause the lease is up and stay with his annoying mother let me say the room we are staying in is not baby proofed and it has a lot of junk in there! Not to mention I have a 8 year old son from a previous relationship like where is my son going to sleep? And what if he's lying about the house and trying to move in with his mom for along time? It's happened before! We literally just moved out last summer and here we are back at square one. Should I just leave and get my own apartment with my kids? They have low income apartments and I qualify for a 3 bedroom 2 bath all I would have to pay is 65 for the light. Their not all ugly either they are actually well kept and nice. Should I just wait till the 12th and see if the house is ready? I'm just not trying to have 3 kids at his moms house where there is not any room in the first place then he works so I'd be there all day bored and alone with his mom who gets on my nerves. And they also have 4 dogs in the house! 😩😩😩 big German shepards!!! Im worried we will be there till I have the baby and I don't want my newborn around nasty dogs.