I started birth control for horrible PMS. I took a 10mcg dose of Lo-loestrin fe and it was great except that I had spotting for most of the month. My doctor increased my dosage for the spotting and changed the brand for affordability. I was put on previfem 35mcg and it has been AWEFUL! I am constantly depressed and overall feel like garbage. I have been prescribed a 20mcg loestrin and I still have 5 active previfem tabs, but am afraid to take them. Can I stop or switch now, or do I have to wait?