You would have tested too early. You would have tested mid cycle , when you're going to be ovulating - not pregnant. You ovulate mid cycle, and would normally get a period 14 days after you ovulate. How long do you cycles normally last? For example, if you have a 28 day cycle, you're likely to ovulate around cd14. So you should be having sex every other day leading up till point and then again after just to make sure. Since you got your period on June 27, you would have either already ovulated or are about to any day now. So just keep having sex and see if your next period arrives. Try not to worry or stress, as this can delay periods. Good Luck.
If your period ended on you could possibly ovulate on July 17th if you have an average cycle 28-30 days. Therefore you could start having sex everyday or every other day a few days before that and go for a least a week in this pattern. You could also buy ovulation predictor kits (OPKs) at a store and test that way as well for when you will ovulate. If you begin to track your cycles you will have a better chance of getting pregnant. However remember it takes time so be patient. Once you ovulate, you need to wait at least two weeks before you can take a home pregnancy test (HPT). Hope this helps! Good Luck!
don't make sex about getting pregnant! and don't discouraged yourself. maybe talk to your obgyn about clomid pills? i am just waiting for aunt flo to arrive to start my clomid!