Missed period...negative test!

Simmy
I should have come on my period today, it has never been late. We have been TTC since August and every month since I have come on as normal. I usually get pains the day before too but this month, nothing. I did a test today and it said not pregnant. I don't know whether to test again tomorrow or leave it a few days (everyone knows how hard that can be!) please help! Xx