This is incorrect information. You can access up to 16 weeks of sick leave through EI and then on your due date or when baby is born (whatever is earlier) your benefits switch to EI. You get 50 weeks of EI (not 52) it's 15 of maternity and 35 of parental, or 61 if you choose the extended leave.
so to answer your question, you can go off around week #24 if you want your maternity benefits to kick in when you have the baby. otherwise your sick leave will end after 16 weeks and you'll have a gap in pay until the have the baby or your maternity benefits will start after the 16th week then you'll run out of benefits wayyyy before baby's first birthday. so it's up to you and your family and what you can afford.
my suggestions would be get some diclectin and wait it out. you'll start to feel better after 12 weeks.