Help am I pregnant is this normal

Okay so normal my cycle is 28-30 days the last two times it was 35 days. This time im on cycle day 49 I had a positive test yesterday and today very light. I took a test based on when I had sex which was nov 25 because my cycles have been crazy unreliable. So today is 21 days after sex and the earliest to show on a test. Well I wiped and had light pink on tissue. I checked cervix is still high and I can't find the opening. Is this implantation bleeding or normal pregnancy spotting im so nervous im gonna lose baby.