Advice for a first time trier ....

Hannah
Hello all,
This may be a silly question but this is the first time we are trying for a small person so I've not been through this before.
My last period started on the 5th March. I'm usually pretty regular and was expecting to start around the start of April. I've not started yet, and not had any signs even after sex. I may be completely premature in thinking there's anything as I've been feeling some mild muscle movements but it got me wondering how long you would go before you took a pregnancy test?
I don't really have any girlfriends in this situation so I thought you guys might help.
Many thanks!