What Causes Sickness, Headaches With Loss Of Lumps Of Blood?

Hi ive been trying to concieve for a couple of months now. So on the 25th April i started my period, which lasted aprox 5 days. My cycle is usually about 30 days so I worked out my next period to be around the 27th. In the first wekk of may, i started feeling sick, getting headaches and feeling odd. Then on the 7th May, i experienced blood loss with lumps of blood. Then i stopped and last night this happened again. I am feeling sick, tired and very irratable and am concerned as to why this is happening.