I usually get about 2 periods a month, one at the beginning, one at the end that falls into the next month (never late) and im late by a month but i took 2 pregnancy tests weeks apart from each other and they both came back negative. what do i do?

Just follow it for a bit longer. if after 2 or 3 more months, then you should see your gynecologist for an exam. At your age, variability can be quite frequent. Are you on birth control pills? Have you skipped any doses? If the answer is "no" to both, then sometimes a few months of being started on such a med can actual re-set the regularity of your cycle. But do this ONLY with your GYN's involved

Wait and either you will get pregnant or you will have periods. Missing 1-2 periods per year is not unusual.. Hope it helps.