losing a job because your pg?

Ok so I'm an Art Teacher. I have my summers off. This summer I wanted to make extra money. This was back in Feb/march I found I was pg in Jan. Thing is I was still in the stages of not sure I was pg and wasn't in the safe milestone yet in early pregnancy. So when I applied for a summer art teacher position at a daycare, I was in a lot of unknowns with my pregnancy. So that being said, I didn't want to bring it up and when I was interviewed, it went so well that I was excited and it didn't even cross my mind that I was pregnant and that I would be very pregnant by the time summer rolls around. 
I got hired. And I went in, got certified, took tests, had my DL and SS card to copy. They even wanted a copy of my diploma. I went through all of that and was officially hired. A week later I was in the daycare writing out my art curriculum while there. Was told to keep in touch by email. 
After reaching I think 15 weeks? I decided, hey I need to call them and tell them I found out I was pg and that my summer teaching can only be during the summer months of June and July  School starts back up during this time in August. And I need some time to prep my room and blah blah blah. I'm due September 16th. School starts August 24th?  Anyway. Not much ask, right? I was only hired for temp FOR SUMMER. 
I was told I was fine. And that she, the owner, was pg and that pregnancy and working is great. No problem. Congrats and we will see you then. 
Sent them an email sometime in late April about curriculum and supplies. Never got a response. Had this deep feeling they were not going to respond. 
Let's just say I had a back up plan. I was going to teach summer art camp and that it would just be two weeks and I made my goal in savings for my baby. I'm happy. We exceeded the amount we strived for. 
But thinking back, those fucking shady people at the daycare didn't reply to me ever since I told them I was pregnant. How cruel!  What if I needed that job and I didn't get the opportunity like I had?  What would you do, say?