Trying to concieve

Toni-louise • I`m 21 and my partner is 22, who also has fertility issues. Has a 4 year old boy with another woman, but me and him are trying for our first baby..
Me and my partner have been trying to conceive just over 2 years, and so far nothing yet. Has anyone has irregular bleeding and not knowing when your ovulating or pin pointing when AD starts?? Because according to my calender I'm 4days late, but took a test and was negative.