So f'n confused

Cara

So I am 5 days late on my period never had a period in February I'm cramping on and off every day I feel like shit headaches. I take tests almost every day and they say no well i leave and come back and check one i took yesterday one said a clear yes and the other a no i have had multiple tests like this where one says yes the next day whole others say no.. Why?? I'm never late on my period i have yet to take a digital