I'm a 22 year old girl. I missed my period which I was supposed to get by the 7th of January 2013. I had sex on the 23rd of December and had used a condom. The condom didn't break, nor did any such mishap occur. Also, I had a lot of stress in December due to my exams and some family problems. I have irregular cycles at times and suffer from dysmenorrhea every other cycle. Now, to be sure I took 3 pregnancy test, all negative. The first test I took on the 17th of January, 10 days after my expected date and it was negative. The second one, I took 2 days later and that too was negative. Then I took one 4 weeks later on the 29th of January which also was negative. I started to worry because I've noticed some clots during defaction. Also, a thin strand of blood like membrane came out of my vagina which was about 4 cm in length and the blood wasn't fresh. I also experience some dull aching pain in my abdomen. I I I have no other symptoms of pregnancy. No nausea, morning sickness, sudden cravings, sore breasts or anything. Now I'm confused as to what it is.. Could you please help me out with this? Its quite confusing, the symptoms.. Thanks in advance..