If i have a blocked tube would it prevent an egg being released???

I know that a blocked tube can prevent fertilisation. I am getting all the signs of ovulation and am getting a period 2 weeks later but a blood test revealed i didnt ovulate. My Dr is sending me for a HSG test where dye is injected to see if there is a tubal blockage but i am not sure if this will matter if i am not ovulating in the first place unless the blockage is preventing ovulation???????