How do I know how many weeks pregnant I am?

How to Know How Many Weeks Pregnant You Are

Wondering how far along you are in your pregnancy? It’s one of the first questions that comes to mind after a positive test. Most women calculate their pregnancy from the first day of their last menstrual period (LMP), even though conception usually happens about two weeks later. This method gives a rough estimate, but it’s not always accurate—especially if your cycle is irregular or you’re unsure of your dates.

The most reliable way to confirm how many weeks pregnant you are is through an early ultrasound scan. Around 12 weeks into your pregnancy, your midwife will offer you what’s known as the dating scan. This appointment isn’t just exciting for catching the first real glimpse of your baby—it’s also crucial for pinning down your due date.

During this scan, the sonographer measures the baby’s size, which is highly accurate in early pregnancy. This measurement helps determine your stage of pregnancy more precisely than counting from your last period. It’s especially helpful if you’ve had irregular cycles or if you conceived shortly after stopping contraception.

If you’re unsure about your dates or think you might have conceived at a different time than expected, don’t hesitate to speak with your midwife or GP. They’ll guide you through the process and make sure you get the right care at the right time. Early confirmation means better monitoring throughout your pregnancy and a clearer idea of when to expect your little one.

Remember, every pregnancy is different. Even if you're not sure about the exact timeline, your healthcare team is there to support you from the start.