Matrilineally Jewish

If you are Jewish then you have an obligation to keep the laws of Judaism. If your mother was Jewish and did not change her religion before you were born then you would be accepted as Jewish. In order to get married as a Jew/Jewess before Jewish Orthodox authorities you would have to provide proof that your mother was Jewish. The Rabbis however would probably be only too willing to help you do this if there was a need. Talk to them. You will not be the first case they will have had and they are on your side.

If however your mother, though Jewish, was born into another religion or changed her religion before you were born then it may be a little more complicated. Nevertheless you would probably be accepted as Jewish but might have to undergo some ceremony or other. At all events, Jewish males need to be circumcised. Do not really on commonly accepted declarations, general knowledge, nor on posts such as this one, etc. Check it out with a competent Orthodox Jewish authority. The Orthodox rulings are accepted by all Jewish groups BUT non-Orthodox rulings are not. In Israel today only Orthodox rulings are recognized. Why create doubts, confusions, or uncertainties? Go to someone who knows and is recognized. Most Rabbis are knowledgeable, friendly, and competent, and resourceful. There are exceptions but they are just that, exceptional. If you do encounter an “exception,” move on. Do not be disheartened. This could involve the most important decisions you will ever make. You owe it to yourself to remove all shadow of doubt one way or other. Good luck and God bless you.