Ttc baby#2.. Not sure what to think

So my last period was Nov 10 and based on ghis app the next period for me is due Dec 9. On Nov 20 I am pretty positive I ovulated which was right on target with when the app said my fertile days were. My husband and I went away during this fertile time just the 2 of us leaving my 15 month old home with my parents and we had did the deed almost every fertile day! At 11dpo i experienced 2 hours of light cramping and heavy urge to urinate and last urination had pink tinge. this afternoon (which is 15dpo) i had cramping and when i peed i had dark red brown thick blood which ithought  was my period so i used tampon. However the blood seemed to disappear like the end of my period usually. Never experienced this was DD but am i maybe pregnant , should i test tomorrow which is 3 days before AF is due?