Hello, since January my cycle has been shorter by about 5 days. Am 17 yrs old. My first period this year was on 1st Jan after counting 27 days. That was normal. On 7th Jan (day 7 of my cycle) I had anal sex with my boyfriend and various forms of foreplay (but not intercourse). I was expecting my period on 27/28th of Jan but it came on 23rd. It was lighter than usual too and lasted 4/5 days. To confirm that it wasn't implantation bleeding I have done 3 urine tests more than 2 weeks after my abnormal period that turned all negative. So my Jan cycle was 22 days. It has been another 22 days since 23rd Jan and I think am on my period again. Today is 15th February and is day one. I had cramping and clear mucus discharge with a bit of pink blood and tissue fragments. Is it normal for day one?
I have also been very stressed about pregnancy and also paranoid, changed my eating pattern and significantly gained weight since my last normal cycle of 27 days. Could this be the cause of my weird period pattern change. Please help me out. I am very worried. Can I be sure am not pregnant?