Could you be pregnant if you've had two negative pregnancy tests but you're not sure when your period is due because they are very irregular?

You could be pregnant!! If you do not know when your period is due it might be you are testing too early I would wait another 2 weeks and test again if you still do not get your period and the test is still negative make an appointment with your Gyne and discuss it with them. A blook test make come back positive or it may be something else.