Hello I Am Seeking Answers. My Last Cycle Was Sep

hello i am seeking answers. my last cycle was Sep 17 2015. it wasnt my normal cycle. it only last 3 days and was so light i didnt need a pad. Now any other regular cycle would be heavy the first 4 days out of 6 days. I took hpt's and all of them came back negative. I took a blood test at the ER and the Doc said it was negative. I tried to ask more questions but she just blew me off as if she didnt have time. Now im not sure what going on. There are some days where i get light cramps and feel like its about to come but nothing happens. Now when i wipe i see clear pink, but very faint. I havent had any vaginal mucus either lately. Please help any informatin would be highly apprecaited.