Maternity Benefits SSS

Good day!  I would like to ask if I still can claim my maternity benefit even without sending notification at sss? It's because I don't have any signs of pregnancy (wala pong lihi and normal po sakin na konti lang ang blood pag may period.. yes po. Monthly pa rin po ang period ko that time) and to cut the story it's too late for me to confirmed that I'm pregnant. I did my first prenatal check up last January 10, 2020 so I can also have an ultrasound copy for the submission of my notification to sss pero that day also my baby was born (emergency cs) , because my blood pressure was too high (delikado na po kami ni baby) and yes my baby was a premie. In that case I was not able to submit notification to my employer or in sss.  If yes po.. paano po kaya ang proseso? Maraming salamat po.