If I’m not pregnant I must be going nuts

I ovulated on the “20th” but really think it may have been the 19th. I started to have cramping and spotting on the 23rd. Not a lot of spotting, I never needed a panty liner or anything it was only when I went to the bathroom. I realize this would be too early for implantation but couldn’t help but hope I was wrong when I ovulated. I spotted for about 3 days then stoped one day and just a little spot the day after. This whole time since I have had a lot of cramping and stretching. I start my period in 4 days. I tested two days ago with a cheap Walmart blue dye test and it came back with what I thought may be a possible positive but not realizing it was blue dye (which I have never used) I went and bought a First Response Early Result test. I took that this am and it was clearly negative. I have felt like absolute crap. No energy, headaches like you wouldn’t believe, and these cramps which come and go. I should also mention we are trying for number 3. I have never felt like this with either of my boys which leads me to think I’m not pregnant but if I’m not what the heck is making me feel so darn awful. Sorry for the long post. I feel like no one want to talk about these things they just want to hear the exciting news when you tell them you’re pregnant.