I feel a hard time telling women I date about my past same sex experiences. At what point should I tell them?

There's a lot of prejudice about this so your hesitation is understandable. You don't owe an explanation about it, so don't worry if you don't feel like saying it straight away. You can wait until you are more comfortable and intimate with the woman you date, if you know each other well and she knows your value as a person, her feelings for you will be stronger than any prejudice. There's no right or wrong time to talk about it, whenever you feel comfortable enough and you trust your connection with her you can consider saying it.

Think to yourself, write it out, what makes sharing or disclosing this difficult? Why would these women be entitled to this information? Why would anyone react negatively to knowing this about your past? Do you want to be with a person who can't fully accept you? How were you feeling when you had these past experiences, and can you be fully honest with yourself about it all? Are your needs going to be met if you keep it to yourself? People tend to be hurt more, the more their partner waits to disclose things. You'll know when the time is right.

Sexual experiences are a personal matter. If you're struggling to discuss those experiences, it could be that you don't feel the need to share them right away. I think that when it comes to sharing specific information it's entirely optional. When it comes to discussing that information, it can be on a need to know basis. Also, when it comes to the when to discuss with a new relationship, or an established one, it's a serious conversation to have...but only one that ideally would only be approached when you are comfortable. it's one of those that if/when you choose to discuss it scenarios.