When EVERYONE You Know is Pregnant

I would like to say that I am generally happy and supportive person, coworker, sister in law, and friend. I have been blessed with ( nieces and nephews and friends with beautiful children. With that being said, I am struggling to stay positive during this season of my life. My husband and I have been trying to conceive since April of 2016. I have visited numerous doctors. My progesterone has been significantly low in the past, but medication did not help. In November of 2017 I stopped having periods and finally had my first one about a week ago (February 2019) which was very excited. Even my husband said "Wow, I never thought I'd be so happy about you getting your period". lol. Anyways, it seems like everyone I know is pregnant or just had children. Last year two of my sister in laws had children a month apart, and now my other sister in law just announced her pregnancy. My best friend had her first child, and is now pregnant again. I have attended 4 showers for coworkers who have been pregnant in the last year in a half, and I only work with around 30 people. I am genuinely happy for all of these people, but I am also struggling with feeling envious. I can't help but feel like something is wrong with me or I'm doing something wrong. Why can I not get pregnant? When one of my newly married friends starts talking to be about how excited they are to start trying I literally just feel like breaking out in tears or changing the subject. Please tell me I am not the only one who feels this way. I feel like a bad person, but it just hurts to feel so alone in this journey.