Talk to Gynecologist on Period Cycle And Pregnancy

my period cycle is 28 days maximum sometimes 26 days and my period cycle is fully normal, my last period date was the 8th of June I have trying to conceive for the last 7 months but have not succeeded you know that today's my period is not coming and the pregnancy strip test was also negative, and I have very pain in the lower back, I'm taking ovabost tablet and co-enzyme my lower back pain is making me down please guide me.