Cramps on CD 20-21, excessive burping, and extreme waves of fatigue randomly

I've like most, googled and tried to find symptoms I've been having to match someone else's.. but not much luck, I've been TTC for almost 7 months now, havent tracked ovulation, but kept up with period chart for the first 3-4 months, the 1st month I ended up at the hospital with unexplained inconclusive test which also lead to 14 day bleeding and I was told it was a miscarriage, had sore boobs for months after, then slowly started only have boob tenderness before af. This month I have NOT had any breast tenderness, but extreme waves of fatigue, bloating, and cramps on CD 20-21, but no spotting that I could see. So with that being said, I usually start around 29-31days every cycle (unless stressed) . The cramps we're light, and vanished after the couple of days, but for the past few days I've had a little bit of stomach cramping (not pms cramping) on and off. I took a test on CD 25 and CD 26 and both were negative.. im really losing hope with my TTC journey as month 1 was a heartache.. I plan to soon start preseed as I've seen alot of women use it and get pregnant instantly, but for this month just as every month, I'm looking and searching for answers.. I don't feel as if after is coming, over having NO cramps or breast tenderness.. please help! Thanks 😖