Lighter period on new birth control

I’ve been on ortho-tri cyclen for a little over 4 years until my doctor switched me to Lessina. She said it was a lower dose and recommended I switch so I did. My first month on it my period was normal, second month was lighter than usual, and now this month was the lightest period I’ve ever had. I’ve always had very heavy periods. It was very light and I still had to use tampons but I’m concerned with how light it was. Even thought it was light it lasted around 5 days. I’m worried it was implantation bleeding or something like that. I’m really stressing because I’ve never had one this light and I don’t know if it’s a possibility of pregnancy or if it’s just the new birth control. I’ve never had birth control make my period like this. Please help!