HELP!!!

ok so im not rlly sure who i should be asking this to but my husband and i have been tyrin 2 conceive for about 8 months and nothin....however my periods hav been late, i have been rlly gassy and im nauseated all the time i have headaches..i itch and my breast are tender but my test keep showin up neg?? what are some of the things him and me could could do to increase our chances of havin a baby? we rlly want one but we just dont seem to be doin somethin right......

Thx u!!!!!