Ttc for 1st time. currently 45 days since my last period started, my usual cycle is 35, but my last cycle was 40. negative hpt at 41days. suggestions?

Late period.: 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).Pregnancy is #1 reason.