Due date HELP

So I found out I'm pregnant. And will be a week or so before I'm able to go to the doctor. So I wanted help guestemating how far along I am. The last *normal* period I had was February 2-6. I spotted for a few days at the beginning of March and didn't have any spotting, or period at all in April or any this month. So should I count it back to my period in February or when I bled in March??? I'm so confused. 😕