Can Clomid Be Taken For Conceiving Soon?

Can I take clomid (50mg) again, it gave me a cyst when I was put up to 100mg , but that was a few months ago and the cyst is gone now, I also have my period so am ready to go, we have had 3 failed ivf cycles and am desperate for a child, I am 41, also can I take 50mg of dhea aswell have heard this is good for egg quality, many thanks melissa