I completely understand having those days where it seems people are like I am pregnant and did not seem to try, but you have to remain optimistic, and can't be a hater. I say this especially at 4 months of ttc. If you are frusterated already, it can be a very lonely and long road if for whatever reason it takes longer than expected, and or it takes you the normal year to get ku.
I never knew when I first started ttc that we would be in it for a long time, and I would watch what seemed like "everyone" be KU and here I am still waiting. I am talking over a year, 18 cycles etc. I tend to be an optimistic person, and I get not everyone is like that so I can understand the frusteration.
You just never know what those people went through, they may have had an easier time getting pregnant and lost other stuff, or maybe it was not as easy at it seems. Not everyone is as open with Fertility/Infertility stuff.
I just wanted to stop by and encourage you to enjoy the process, and try not to let it get to you so early on. I am hoping that you get that BFP real soon! Hang in there<3