Week of spotting off and on negative tests

Sunday the 22nd, I've had spotting in the morning time. It goes from a red color to light pink/brown after a few hours then stops all together. Here and there have had some heartburn and mild headaches and mild cramps not too horrible to take midol. Feeling bloated. Just a bit odd for spotting only in the mornings. We've been using the withdrawl method lately. I'm sexually active. Not on birth control. It finally stopped today. Still have headaches and mild heartburn. I get nauseous here and there as well. Tired more. I tested last week and it came back negative shouls i retest this week to make sure since my spotting stopped? What should i do?