"If I remember correctly" is a idiomatic way to express that you believe your recollection of information is accurate. It's a commonly used phrase in English and would be a suitable choice in most situations where you are trying to recall something from memory. It's a polite way to preface your statement, indicating that there might be a chance of error.

For example:

If I remember correctly, this painting is from the 18th century.

If I remember correctly, the store closes at 9 PM, so we still have time to shop.