The size and location matter in regard to complications and blood clots.

In general; uncomplicated hematoma should resolve in 4-8 weeks.

It sounds like you are doing all the right things. Keep in mind that the progesterone may increase your risk for blood clots. Stay well hydrated.

Consult a surgeon if you develop any problem.

Usually a hematoma in the setting of blunt trauma is enclosed in soft tissue and not intra-vascular. Therefore it does not increase risk of blood clot and thrombosis. However, if the hematoma is close to and compresses a vein, it can increase risk of DVT or blood clot in leg veins. This is extreme rate.

The hematoma should not pose a realistic risk for forming a clot in your veins. It should get gradually smaller as it is reabsorbed by the body, although the process may take months. If it enlarges, becomes more painful, appears red or infected, or your leg starts to swell, then you should see your physician immediately. Although the ASD is a potential concern, it is only significant if a blood clot formed in your veins, dislodged and traveled to your heart, and the repair had not ben successful. There are plenty of people with an ASD who have had an uneventful recovery from a similar injury.

If there is a concern it is always good idea to check in with a doctor.

You are at a higher risk for deep vein thrombosis due to your accident. It is not a hematoma that causes it, but trauma itself. So, no long sitting, walk more. If you see any swelling in your calf or leg that getting bigger, go to ER or doctor for US vein right away.

Continue to treat as you are unless it begins to hurt or show signs of infection(swelling, redness, drainage, pain, fevers). The hematoma is outside of your blood vessels so you do not have to worry about it causing a clot in your vascular system. You are at a slightly increased risk for clots in your vessels from the trauma itself but not because of the hematoma.

See a doctor please.

First of all, I'm sorry to hear of your accident, but am glad you had no serious injuries. By definition, a hematoma in your thigh is a collection of blood that has gathered and collected in your thigh as a result of your accident and will show up as sweeliing and bruising in your thigh region, most likely within the muscle layers. If the bruising so far has greceded some, that means that some of the blood has already been reabsorbed. This is usually a slow process to complete and could take months for it to completely resolve. If the extent of the bruising expands or the area of sweling increases, then that may be a sign of NEW bleeding and if you see that, then you should immediately see your Physician if that occurs. If you have an ASD, then you could be at risk for any venous clots to flow from the right atium to the left atrium via the ASD. The clots would then enter into the Systemic Circulation and if they travel up into the brain, could then result in a devastating stroke! However saying that, if you had your ASD closed by the repair already, that risk should have been minimized already for you. Also, the hematoma in your thigh in located in the muscular tissue and not within the veins of the legs, so I do not think your hematoma poses any risk for clot formation in your veins. If you want to rule out any residual ASD flow or defect, I would recommend a TEE or transesophageal echo to investigate the atrial septal region in a relatively non-invasive fashion for any residual right to left flow, but there should not be any after a successful repair.