So tomorrow I go into my new job to turn in the last of my papers and get a tour of the place and…

So tomorrow I go into my new job to turn in the last of my papers and get a tour of the place and then i start training on monday. This whole process has taken about a 3 weeks or month and I've kind "exploded" since then.. I didn't mention being pregnant when I first did the interview but I did mention needing time off in August. Im curious about how Im supposed to go about telling them and when and all of that.. Anyone have advice?