Cycle Day 4 i'm still crying.

My sister in law always starts her af before me approximately 4 days. Her and her husband have had problems for a long time and they don't sleep in the same room. But it happened that they baby dusted once only. Coming to my part I have been trying to get pregnant about 6 months and every month that passes I say next month. Her period was late I told her to check she said no way. On Saturday af came for me and she turned to be pregnant. I cried and cried and still cry everyday. Why? Why? Why? Now I'm going crazy because I have af and I af to see that I'm not pregnant.... I just needed to get it out... Baby dust to you all