the 3rd day the 30 ug would feel like 15ug.
but if you give a break of 2 days from such a low dose - on the 3rd day after your last dose 100 ug will seem like 100 ug.
the best is to skip 2 days even for micro or mini dosing. (30 ug is kinda minidosing, you will feel it quite a bit.)