1. How long does it take to start feeling pregnant? How long does it take to start experiencing pregnancy reactions is a common question, but the answer is not set in stone. Generally speaking, there are no obvious symptoms from the first to the fourth week after pregnancy. But starting from the fifth week, many women will begin to experience physical changes, such as breast swelling and pain, nausea and vomiting, fatigue, etc. 2. How long does early pregnancy reaction last? Early pregnancy reaction persists