I got pregnant on my period so I would wait about three days and take a test.
Do you check your temperature to see when you are ovulating?
Using the calendar alone can be inaccurate, it is only an estimate. I've heard of women getting pregnant when they had their period. The egg doesn't always drop when you expect it too.
I think that there are ovulation checker kits out there now, if this is the method that you want to use.
Are you usually regular with your periods? That is what I would be looking at.
Yes, I think it is possible you might be pregnant, but worry about it might just delay you from getting your period when you're not pregnant, so try and relax and not think about it until you decide to take a test.