spotting during fertility window

So AF finished last week. Sunday was the first day of my fertility window according to Glow so my husband and I have been actively ttc. Today, I noticed some light spotting that was bright in color, not dark like old blood. What could this be?? I also had some lower abdominal pain that started last night and continued into today. I'm hoping it could possibly be spotting from implantation by I don't know much about any of it. This is our first time ttc and we've been trying since August. Any input is very appreciated 😊