Cycle buddies mar 16th?

Verity
I was due to start at mar 16th and nothing. I'm fairly regular, within a day every month. Been having minor cramps occasionally, sore breasts for a week and nausea every day last week (although not last few days). Today is my birthday so took a test hoping for a nice present! First one was a dud, wasting my first pee :( went out to buy another at 6am and drank a litre of water to force another pee! Bfn :( test again tomorrow or wait  a bit longer?