Pregnant or late period

So I am going on 50 days without a period. Longest I have ever gone. I did have unprotected sex, but I always get my period, except not this time around. I haven't had symptoms, except last week I had spotting. I know for a fact it wasn't period since it was a light pink when I used the restroom and then it would go away and would continue a few days and then stopped. Could I still be pregnant? Last test I took was last week and it was still negative