Faint lines for three days ( Period suppose to start tomorrow )

Me and my husband have been trying for two years now with a miscarriage in btw. We have a 3 year old. I have just been testing to see if I got pregnant this cycle with no hope but I saw a faint line starting Sunday. But it’s super light. I’m really nervous and scared because it hasn’t gone really much up and it’s already been 3 days and I hope it’s not going to end in a miscarriage. If someone who had similar experience or any feedbacks are welcome! Thank you! Baby dust to everyone who is tryingggg! 🙏🏽 💜