Clumps in breastmilk?

So I've been pumping pretty much exclusively and supplementing occasionally with formula.

Today on two different pumping occasions, I noticed a small clump transfer from my pumping bottle into the feeding bottle. What would cause this? Is it okay to feed baby this? I tried to pour the milk slowly back into the bottle to see if I could find the clump but it must have dissolved or something?

I'm new to this breastfeeding journey so I'm quite confused.