Three Days Prior To My Menstral Cycle I Had Severe

Three days prior to my menstral cycle I had severe cramping that kept me up for several nights. In addition to the cramping I have been experiencing nausea, bloating in my stomach, back and hips. The nausea & bloating have been so bad that I have forced myself to vomit. I saw my OB today, who suggested it might be a UTI, but I don't think so. I've had UTI's before and have never experienced these symptoms.
Can you tell me what wrong with me?