they sound like they are kinda slow but my seedlings allways seem to take forever to get goin too. be patient they should pickup soonmore details would b helpful do they look healthy? i allways see other peoples plants at 3 weeks old n think those are huge compared to my seedlings maybe some strains start slower then others? im not sure but more details will help some of the veterans on here tell u if somethings wrong but id say theyre ok as long as they look green and healthy