Could I be pregnant?

I have been trying for 3-4 months and last month my period was lighter than usual the first day and shorter so I thought it wad implantation bleeding but it got heavier near the end so I thought it was too much for implantation bleeding. And this month my period was due two days ago but I had no spotting or any signs it was coming. I pushed my period was late on the app and it changed it to tomorrow as a start date. So could I be pregnant? When should I test I was thinking of waiting and testing tomorrow if it doesn't come but I'm not sure??!!