When would you test?

Judi
OK, so I have an irregular cycle even on Clomid. I have never had a positive OPK test but have had 2 miscarriages so I know I ovulate sometimes. Glow says my period should start the 14th and and a site I've used just for tracking purposes says the 18th. I haven't been feeling well lately. Would you test on the 15th or wait until the 19th to test?