I just don't understand

I just don't understand like how I have been feeling like crap over the last week. Head aches, nausea, feeling extremely tired and wore out. I kind of got my hope up for taking a pregnancy test talked it over with my husband and got a little excited about taking one. And well... today starts aunt flow but it isnt due for another 4 days. Been trying to convince now for three years. But yet every month nothing. I'm just fixing to lose hope. But still should I test even if it is still light?