How to tell?

How could I tell if I’m losing milk supply? I had EBF my 10 month old baby up until I went back to work on Oct 1st and continued to pump there but I don’t get too much so baby girl is supplemented with formula during the week while at babysitters. I fear I may be losing my milk supply.. when I get home my baby nurses but still seems very unsettled after and unlatches and latches during the feeding. I eventually give her a 4oz bottle of formula in the evening and she’s finally content. I nurse her to sleep still and she wakes once or twice a night and nurses normally, I feel my let downs and all. Idk.. I’m hoping the weekend will help maintain my supply since I’m home all day with her!