drop in supply on period?

anyone experience a drop in supply while on your period? I think I just started mg first period, 8 weeks pp. I'm sad because I didn't have a period with my first until we weaned at 15 months. anyways, my supply has decreased the past 2 days. I'm trying to figure out why, and was just curious if it correlated with my period. if so, how do I prevent this in the future/ what advice can you give?!