If you didn't get your period while on the sugar pills, it's not necessarily a sign of pregnancy. Many women have very light or no periods when they first start taking the pill, it's a side effect.
If you are asking if it's safe to intentionally skip a period by skipping the sugar pills and moving on to the next active pill pack, it's not usually a good idea when you first start taking the pill because breakthrough bleeding (bleeding in the middle of your cycle) is common.