Day 1 of my period was march 4. I had intercourse with my husband march 15 & march 18. I had a light brown spotting on my pantiliner yesterday, march 20 (morning upto afternoon. No more spotting in the evening). Could it be implantation? Please help i'm kinda new at this. And by the way, i have a retroverted uterus. Will that info help? I want to get pregnant already. We've been trying for months now. Thanks in advance!