Any advice welcome....

Me and my boyfriend have been talking about having a third child. It's becoming very difficult because I am not having normal periods at all. I have never been regular, but I have always had one. In 2014, I had a period in April and then not again until July and then nothing till Sept and then again in Oct and nothing since. I have taken numerous pregnancy test and they are all negative. I hate going to the doctors, so I was wondering what other people have experienced. Please help!! I really would like to have a baby this year.