Congratulations on your pregnancy.
I'd be calling the hospital today to orgnaise some sort of antenatal care if you have not done so already. Give you were 16 (at least) you will be fine, and as others have said thehospital wont generally concern themselves with it.
It should be fine but I am pretty sure in most states it is legal ot have sex if you are over 16 AND your partner is not more than 2 years older than you at the time..
Consent laws in Australia vary by state, but once you are 16 or over its fine. It's if you are under 16 that the 2 years older comes in to play. For example in some states its legal for a 12 year old and a 14 year old to have sex, but not a 12 year old and a 15 year old. And some specify that its the female who is to be younger