ovualtion question

On April 25 I got a lupron injection(3 month), followed by a very heavy peroid on May 12.  In June I went to have my estrogen check and it was very high, so I had a booster shot, followed by another heavy peroid on June 15. The nurse said  to have intercouse EOE at the end of July to hit a ovuation. ( I have stage 3 endo and never have problems with ovulation and cycles are like clockwork every 28 days). I have taken several ovulation tests all were neg.  So i was wondering where I would be able to track my ovuation...start from June 15?  The nurse also said to call in Aug with a pos or neg test, but im not sure how long i wait...till i get my peroid?  Oh and also last week I was spotting the brown stuff, so i thought my peroid was gonna start, but after a few days it stopped.  She said the booster shot wouldnt pro-long my peroid, but ive read otherwise.  any advice ill take..thanks!