Write an article based on this "Don't be embarrassed. Keep it simple. Try a pre-made note online. Ask to talk to a female you both trust. Ask him to schedule a doctor's appointment for you. Talk to someone else."
Remember, menstruation happens to all girls; in fact, it even happens to some female animals. The important thing to remember is that the apprehension you are feeling will lessen over time. Know that your dad is mature enough to handle "the period talk." As an adult male, your dad not only knows what a period is, but has probably been expecting to have this talk with you for some time. Your dad may be slightly embarrassed as well. Take comfort in knowing that you're not the only one trying to get a handle on your emotions. Understand that your reaction is a normal one. Starting your period can be both confusing and emotional. Sometimes the easiest way to approach the situation is to just say, "Dad, I got my period." Keeping it brief and to the point will help you to avoid becoming emotional. Instead of building up to a big sit down conversation, try approaching the subject during down time such as when watching television or eating dinner. By being direct, you avoid confusion and open the lines of communication between you and your dad. Your openness may ease his discomfort and he may become a valuable resource for information. Sometimes it's easier to write words than to speak them. But what happens if you can't find the right words to say or write? There are scripted notes online that can be addressed to anyone and that allow you to ease into the topic. With titles like "guess what" or "we need to talk" it sends a clear message to dad without the awkward talk. The great thing about this option is that it informs your parent, but puts the responsibility of initiating the conversation on them. Be sure to put the note in a place where your dad is sure to find it, and make sure he'll find it at an appropriate time. Giving the note to him when he's running out of the house for work isn't the best option. Sometimes it's just easier to talk to a female about female problems. If you don't have a mother or older sister around, tell your dad that you need to speak to a female about "female issues" you are experiencing. Your dad may become curious or worried at this point. You can ease his curiosity by simply stating "I started my period and I would rather talk to a woman about it." You can make your dad feel like part of the process by asking for his advice about who to go to for help. As someone who is in charge of your healthcare, your dad will probably ask why you need to visit the doctor. At this point you can inform him that you are having a personal issue. This will either open the door to further communication or give your dad a clue that something is going on. Your doctor is not only a great source of information, but they can also assist you in telling your dad about your period. A close alternative is the school nurse. You can always get feminine products from your school nurse while you're figuring out how to tell your dad. But don't hide it from him for too long. It is definitely something for which you don't have to be ashamed. What happens if your dad isn't someone you can trust or if he is embarrassed by the situation? You can always choose to confide in a trusted confidant like a family friend, relative, or a trusted neighbor.