I am in my second trimester and I keep scratching my body all day. What's happening? Is this normal?

It is normal. Your hormones are at its peak. Try also to avoid foods rich in histamine like chicken and eggs, and such seafoods and vegetables, it can help lessen the itchiness. Also choose your detergent that are Phosphate-free and bath soap that is hypoallergenic, it will help. Scrutinise every product you use at your body