Since these spots seem to be getting worse with time and not going away, I would strongly recommend that you set up a visit with either your primary care doctor
or your dermatologist
to help you figure out what is going on.
One possibility is that these represent freckles or "sun spots" which can often develop over time due to damage to the skin from sun exposure as well as the normal aging of the skin. If your doctor confirms this as your diagnosis, then there is generally not much you can do to get rid of the spots, although protecting your skin with a good moisturizer and also with a sun screen can help to prevent them from progressing more.
Another possibility is a condition known as melasma, which involves the emergence of dark areas of discoloration on the cheeks, nose, and forehead. Melasma is often genetically determined, but it can also be associated with certain medications (such as birth control
pills). If your doctor confirms this diagnosis, it may be possible for you to try a number of different prescription creams which may help to even out your skin tones and, at a minimum, lighten up the spots a bit.
Go see your doctor when you can!