very frustrated

We've been trying to conceive for about 7 months now.. I'm a couple days late on my period and I did some calculations so I found out I ovulated on the 31st of march and it says if it implanted then it would have on the 6th of April had all the symptoms and what not and now here I am at "12 dpo" and still no period no signs of it I got a faint positive yesterday but today I test and nothing at all.. I just wanna understand but I know that'll never happen.. it would just help to hear how some other women's bodies are. It's frustrating trying to conceive, if I didn't I'd just like my period to show up so we can try again. I was due for my period on the 9th