Hard to tell, but they are definitely swollen calyxs. You say you pulled a few off and they were empty, so chances are it's not seeded. Some strains calyxs swell more than others, you may just have one that swells a bunch. Usually the preflowers at the nodes swell before the rest, they were on the plant first. If you are at 2 months it's perfectly normal and that late in the game I wouldn't worry about too much anyways except for flushing.

My :twocents: