I am 23 years old and have had rather normal periods about ed flow for about 5-6 days. Well this time I spotted for a couple of days and then started my usual flow period however, I am now on day 16 of my period with no signs of slowing down or anything. I have never had a pelvic exam and rather not due to my past. What could this be do I need to freak out? I know I should go to the doctor but is there a way that I can request that they do a blood test first to rule out things such as thyroid or hormonal problems?

I have not been on any new medications or anything out of the ordinary.