TTC Period Due 21st Of Oct. PLEASE READ AND GIVE ADVICE.! HELP.!

So My Last Period Was Sept. 21- 26.. Normal Period Start Light Heavy Then Light Again.! So A Week And A Half Passed And On Oct. 6th I Got Some Real Heavy Bleeding With Clots.! I Was Concerned So I Went To The ER And Called My Dr. Apparently Nothing Was Wrong And They Sent Me Home.. It Lasted Two Days.. After That Nothing But Normal CM.. Me And Hubby Had Sex Right After And Before The Bleeding.! Then The Usual Every Other Day Sex.. Now My Lower Back Is Cramping (Dull) And I've Been A Little Nauseous And Sleepy.! I've Also Been VERY Constipated.! I Don't Want To Get My Hopes High Because I'll Be Kind Of Disappointed.! The glow app Is Saying My Period Is Die On The 21st But My Periods Are 26 Days Apart.. So That Can't Be Right.. Any Suggestions.? Has This Happened To Anyone Else.?