silicone on silicone caulk

I just installed a kitchen sink on a tiled counter top. I layed a bead of silicone under the lip of the sink and put the sink in. Then tooled the caulk but after sitting for a day I noticed I must have missed some spots, should have added more caulk after the sink was in place. After doing much searching and reading a bunch of posts on silicone caulk I'm not sure if I can just add more silicone on top of the silicone I already used or if I need to totally scrap all the silicone out and start over? Thanks for any help with this and hopefully I won't have to scrap everything!