24 year old TTC#1

Maria • I’m 26 years old TTC #2! I have a 16month old baby boy. We have been trying for a while. My period was regular before getting pregnant with my boy, after he was born it took exactly a year for me to get a period again.
I had Nexplanon since 5/8/15 and had it removed on 8/5/15. Before going on BC I had regular periods around the 5th. I did not bleed or had my period during BC. We tried for the first time without protection on 8/6 a day after removing BC. On 8/8 I had cramps and started bleeding a little, on the next day the bleeding was heavier and more red. By the 3rd day I was not bleeding at all. Could this have been AF? Also could I have get pregnant on this week? I want to take a pregnancy test by the 20th but I don't know if that would be too soon.  Glow predicts that my most fertile day is on the 21st so we will keep trying on my fertility window. Prayers and Baby dusts are welcome😊