trying to convince my 3rd baby

ma
Hi I am a mother of two beautiful children a 4 year old and a two year old my husband and I decided it was time to expand our family and are trying for baby number 3. We have only been trying for 2 months and so far negative pregnancy test. Any ideas or suggestions on how to conceive fast? My kids were both accidents so this is our first planned child and I don't know any Theories about how to get pregnant.