Baby probs

So me and my boyfriend have been trying to have kids for 4 months now and I recently took a test and it was negative. It make me feel like crap know that there are people my age who are accidentally getting pregnant and I'm actually trying. The other night I went over to a friends house and her cousin showed up with her baby boy. They went to go cook some food and left me with him... I held him and he looked at me and giggled and smiled and I immediately butts into tears... I just want to have a baby with the love of my life and I don't know why it's not working out. 💔