Becoz the month of jan late came my period. With neg result also. Feb19 I try pregtest n it neg. My period stil not come this month. Jan last came 26-3o?

Irregular Cycles. Irregular or delayed menses are usually caused by pregnancy or not ovulating. If the home pregtest is negative then likely not pg but blood test better (consider). If you did not ovulate, then it could be by chance or you might be changing from regular to irregular for ovulation and menses. Perhaps a change in weight (up or down), medications, stress, or even diet supplements. See doc for tests.
Late Menses. If you are regular with your period being late suggested that you are pregnant, and you should at least do a home urine test. If you're not meaning that you have a late cycle (and you're usually regular) you probably haven't this cycle or the ovulation is late. Keep trying and you eventually will conceive.