finally got my bfp!!! no idea when due date is?

So I have pcos and my periods are irregular and I'm having a hard time calculating when my due date might be. I took a test on Monday and it was negative, however I took two digital tests an hour ago and they say pregnant. The first day of my last period was may 5th. Is there anyone that might be able to give me a guess of what it might be? I'm making an appointment with my doctor to verify. My husband and I are just curious. Thank you!