Period late

So it's been about 4 years since I was pregnant and I don't really remember how long I can wait until I take a test. Going on 4 days late now. Fatigued but frankly, I'm always tired because I have insomnia. My breasts are tender but they always are during my period and before my period. I had some cramping in my lower back last night. Should I wait a couple more days or go ahead and take a test?