Gestational diabetes question

Mom • My name is Raschel. I`m married and have a wonderful 4 year old son and a beautiful rainbow baby girl born nov 2016.
I'm almost 27 weeks pregnant and I did the testing once already earlier in my pregnancy. I was just wondering if anyone opted out of having it tested a second time. I can't really afford to do it and my insurance doesn't really help much. Any information would be greatly appreciated!