I am 10 days late for my period, which is weird on its own because I'm very regular. 7 day period with heavy flow every month without a doubt. I should have started on the 18th and still no regular period. I have had a little spotting but it's a brownish black mucus- y discharge instead of a blood like spotting. My boyfriend thinks it's impossible for me to be pregnant after doing the math from when I had my last period and when I should've produced an egg compared to when we had sex. What should I do? ( thanks for anything you have to offer)