Absolutely feel free to post your stories. Some of our finest writers are femsubs, woodsman's game, to pick one out at random.
Remember, above all, you are writing for your own pleasure and not to make points with, or impress, anyone else. Those of us who are experienced reviewers, always check a writers previous record of posting stories on this site before we produce our review and we try and be especially considerate of new authors.
One final tip. After you have completed your story sit on it for about a week. Then go back and give it a final polish. You will be surprised how much of a difference it makes. In particular, check for malapropisms (synonyms that pass spellcheck but have very inappropriate meanings) and if the work is longer than about 7 or 8 pages divide it up into chapters. For and example read through a few of the new stories on the story section of the site.
Welcome and good luck!