When you're not sure about something, the phrase "having one's doubts" can perfectly describe your state of mind. However, if you're looking to add some variety to your vocabulary, there are plenty of alternative synonyms available. You might say you're feeling uncertain, skeptical, or apprehensive. If you're feeling hesitant, dubious, or even suspicious, you could also use those words to express your doubts. Additionally, you might say you're questioning, second-guessing, or even hesitant to commit to a decision. There are plenty of different words you can use to describe your "having one's doubts," so it's worth exploring some of the many options available to you.
