When should I take a test

Since March 2015 I've been having irregular cycles, I normally have regular cycles but March I didn't have a period or January or February so I went to a ob gyn on Feb. 27th and the doctor took blood and urine pregnancy tests and they all came out negative and on Feb. 28th I got my period. So every month since Feb. 28th I'll get my period on the last two days of the Month like for example I'll get my period on the 28th or 29th of the month and my cycle would last for 5 to 6 days and it was one time I've got my cycle and didn't have no cramps no symptoms of coming on and I normally would have a pimple or a bad headache. But anyway I didn't have a period for the month of June and me and My Husband are trying for baby #2 after 5 years and lately I've been exhausted and I've been having a sharp pain in my pelvic and stomach and have cramps from time to time but no menstrual. I don't want to get my hopes up and be disappointed again so what should I do????? Please Help any advice???