HELP! getting myself upset am i not pregnant after all?

We have been TTC for 4 months now and every month ive took a test but knowing deep down i wasn't pregnant. This month is different i haven't rushed in to taking a test we did the BD on all the right days. I feel calmer and 2 days before ovulation we had and i just had a feeling that that was the time we had conceived. But now i am disheartened, my period is due tomorrow and last night after i bled very lightly and was very Bright pink. This morning is brownish discharge but not constant and isn't seeping onto underwear. I would like to think it was implantation bleeding but all research i have done leads me to think i should have had implantation bleeding over a week ago if i did conceive. Any advice would be deeply appreciated.