Share your thoughts please!!

So I normally get my period for 6 days. Once in my life I have had a four day period. Now my period only last for two days which is odd. But the first day my period was heavy as usual and the second day it was medium light now on the third day i have seen no blood except for some light pinkish discharge. I had sex once this month near to my fertile days BUT we use Condoms and I made sure he use the pull out method plus with the condom on, also I did the water test with the condom after we finish and there was no such holes. I am trying my best to avoid pregnancy at the moment. Can someone please enlighten me on this. I will be very great full for your help. A little advice can go a long way.