Its been 43 days since the first day of my last period and i'm not seeing any signs of another one. should i be worried?

Not necessarily: Reasons for missed / late period include: an anovulatory cycle in which no egg is released, marked v or ^ in weight; eating disorder; over-exercising (endurance athletics), travel, significant illnesses, oral contraceptives ; other meds, illegal drug use, breast feeding, hormone imbalances and medical problems (i.e., pcos). Take pregnancy test if sexually active.