Menstruation... Severe low supply

I now have my second period since my daughter was born. She is 7 and a half months and as soon as I started solids my period started 28 days there after. My biggest issue is how drastically my supply has dropped the days leading up to and the days during my period I pump 2 oz a session per boob versus my normal five a boob a session. I have never had supply issues and I really don't know what to do and had to supplement this morning before daycare because I feel like I'm almost dried up. This happened the first time but it was the weekend so I assume I didn't notice as much, my supply returned to normal right after my period ended.