What Should Be Followed To Conceive At The Earliest?

my boyfriend and i been trying to have a baby we started back in the middle of may and a couple days later i got a preg test came back neg...tried again a few weeks later taking the test neg...and between then and now hes ejaculated in me a few times i lastly checked again 3 days ago and still neg....idk wats going on is it becuz its still to early? or its the preg test? i got the preg test at dollar general..or i may be doing it wrong but i followed the instructions..idk could u help me