I need baby dust!

Li 💍 • 🍎Teacher 💍Wife 👼🏽Mom to an Angel 7-31-19 and my rainbow baby 7-20-20

AF came right on time this month. The very day that it was estimated to come. However, this time what came out was only brown. I had absolutely no red blood. It only lasted about 3 or 4 days. usually AF is about 6 or 7. I've been nauseous 3 days this week. AF is due in 4 days. My husband and I have been praying and believing for a baby. My question is when or IF I should take a test or not. I have a very irregular period. I didnt have one for most of 2017 and it came this year the night before my wedding in April(that's a whole other story lol). I've had AF every month since. Pray for us! Send baby dust!