Should I harvest

It seems like the buds aren’t getting any bigger these past few weeks? Should I just harvest them?

No not yet. I would check to make sure they are getting 12 hours of dark. and the soil dies between watering. Are they Autos?

I find that in the final three weeks of flower a lot of the bulk comes from within the bud and is a bit harder to see the progress. You will notice the stems/plant is asking for more support from mass being added.