Very scared about maternity leave

So I work at a daycare and called corporate yesterday asking about paid maternity leave. I was told I needed to opt in for the short term disability in order to get paid time off. In November during open enrollment, I declined that choice. We did not know we were going to have a baby. I think I screwed myself out of paid time off and am not going to get maternity leave to take care of my little one. I'm really worried and scared about financials.