Your action on these should be guided by your sexual practices: if you have not been sexually active in the last 4 or 5 months they are unlikely to be sexually related. If you have been sexually active, particularly if you do not have a regular partner, and, do not use a condom each time, is to go and get checked out with a Doctor.
There are several things that can look like this, most of them relatively harmless - they could simply be pimples, for example. What you need to be vigilant of is if they change appearance, in particular, if they become red in colour or burst and emit a substance. If this happens you must see a medical professional …