Hi Past Few Month I Have Noticed My Cycle Has

Hi past few month I have noticed my cycle has gone all messed up I come on verry light for 5-7 days then after 2 weeks I would come on again spot few drops of blood like for 2 days then after 2 weeks am back on my monthly cycle but it's verry light bleeding..... Also really bloated and weight gain....... It has also caused me insomnia really bad! Does anyone know what might b causing it?