At 7 weeks pregnant, your uterus is roughly the size of a large lemon or a small orange, slightly bigger than your fist. It has grown from its non-pregnant dimensions of about 3 inches long and 2 inches wide to become fuller and more egg-shaped, though it’s still tucked entirely within your pelvis and won’t be visible from the outside.
How Much Your Uterus Has Grown
Before pregnancy, your uterus weighs about 1 ounce and measures roughly 3 inches long, 2 inches wide, and 1 inch thick, comparable to a lemon or a clenched fist. By week 7, it has already started expanding to accommodate the growing embryo and the fluid and tissue surrounding it. The shape shifts from a flattened pear to something more rounded and egg-like.
This growth is modest in absolute terms, maybe half an inch to an inch larger in each direction, but it represents a significant percentage increase from baseline. Your uterus is also becoming softer and spongier as blood flow to the area increases dramatically.
Why You Can’t See a Bump Yet
At 7 weeks, your uterus sits deep in the pelvis, well below the pubic bone. A doctor performing a physical exam wouldn’t be able to feel it above your pelvic bone at this stage. That typically doesn’t happen until around 12 weeks. So if you’re wondering why your belly looks the same, or why any bloating you notice seems to come and go, it’s because the uterus simply hasn’t risen high enough to push your abdomen outward.
Any belly changes you notice at this point are more likely from bloating, water retention, or hormonal shifts in digestion rather than the uterus itself.
What the Embryo Looks Like Inside
The embryo at 7 weeks is about the size of a blueberry. It’s a tiny structure within a much larger space: the uterus, the amniotic sac, and the developing placenta together account for most of the uterine growth at this stage. The embryo’s heart has been beating for about a week or two by now, with a normal heart rate in the range of 120 to 154 beats per minute. That rapid fluttering is often visible on a transvaginal ultrasound, though not all providers schedule a scan this early.
Physical Sensations From Uterine Growth
Even though the size change is small, your body registers it. The ligaments that anchor your uterus to your pelvic walls are beginning to stretch, and many women feel this as mild cramping, gentle tugging, or pulling sensations in the lower abdomen. These are sometimes called round ligament pains, though that term is more commonly used later in pregnancy when the stretching becomes more pronounced.
Other common sensations at 7 weeks include:
- Pelvic pressure or heaviness. A feeling of fullness in the pelvic area, caused by the growing uterus and increased blood volume in the region.
- Lower back discomfort. A dull ache that comes from hormonal changes loosening your ligaments and joints, combined with greater blood flow to the pelvis.
- Frequent urination. The expanding uterus presses directly on your bladder at this stage, which is why you may feel the urge to urinate more often even though you’re not drinking more water than usual.
These sensations are typically mild and intermittent. Sharp, one-sided pain or cramping accompanied by bleeding is a different situation and worth reporting to your provider promptly.
How Growth Progresses From Here
The uterus grows steadily but not evenly throughout pregnancy. Between weeks 7 and 12, it roughly doubles in size, transitioning from that lemon-to-small-orange range up to about the size of a grapefruit. By 12 weeks, the top of the uterus (called the fundus) rises above the pelvic bone, which is when your provider can start measuring it during routine appointments and when a visible bump begins forming for many women.
By 20 weeks, the uterus reaches your belly button. By the third trimester, it extends up near your rib cage and has grown to roughly the size of a watermelon, weighing over 2 pounds on its own before you factor in the baby, placenta, and amniotic fluid. The journey from fist-sized to watermelon-sized takes about 33 weeks, and at week 7 you’re right at the beginning of that curve.