nexplanon

a week ago I got my bc taken out of my arm. it came out during my fertile window (2weeks till period) and my SO and I did the dirty. Then 4 days later I spotted dark brown with occasional pink in it. I've had headaches all fricken week, despite how many naps I take or how long the nap. I'm starving but never seem to know what I want to eat. I've been moody and find myself randomly crying over silly things ( like a spam email my SO got) and to top it off I looked at my calender and should be starting in 2 days (the spotting was only 3 days ago) is it too soon to be prego???? how much longer should I wait to test??? everyone thinks I'm crazy