Period was January 12th ovulation predictor on January 19th and 20th and 21st showed lines of positive. Intercourse right in the middle of those days. Around the 28th had mild cramping. Now for the last 2 days have had menstrual like cramps with mild naseau, i usually do not get until a couple days before my period. I usually have a period from 28 to 30 days. Just wondering if this is implantation or if i should be worried about a cyst. i have had a cyst but the pain for a cyst is much worse and did not last a couple days.