Hi, I am an American Board Certified Neurologist and I am very glad to help you with your health concerns.
Based on the details provided by you it sounds like you have not sustained any major or serious head injury due to this incidence.
Developing some headache, and tenderness etc in the hit area are common symptoms after hitting the head against something and these symptoms themselves do not imply any serious head or brain injuries or bleeding etc. There are certain major neurological symptoms if present raise the suspicion for a major head or brain injury or bleed, for example symptoms like prolonged loss of consciousness, recurrent vomiting, severe dizziness/fainting, facial droop, paralysis or weakness or arm or leg muscles, confusion/disorientation, occurrence of seizures etc. If you are not experiencing any of the above mentioned major symptoms then this injury is unlikely to be serious. On the otherhand if you are experiencing any of the above major symptoms then you need to visit the emergency room for a thorough clinical examination and further evaluation. Since you are pregnant a CAT scan is not safe, however if absolutely necessary it can be done by shielding the abdomen by x ray resistant techniques, or even safer MRI can be helpful too. The current sequences of MRI are as good as CAT scan to detect bleeding. However if you are not having any of the major neurological symptoms mentioned above then there is really no need for any CAT scan or MRI scan of the brain.
Once again I reassure you that if just some headache & tenderness etc are the only main symptoms then this is most likely not a serious head or brain injury or bleed, on the otherhand if there are any of the major symptoms mentioned above present in that case you need to visit the emergency room as soon as possible and undergo a thorough clinical evaluation/examination. But most likely it is not necessary based on what information you have provided here, and also it is already about 10 hours since the incident so it is unlikely you have developed a major injury or bleed but it is still not manifesting, so this appears to be a non-serious type of head injury and you should recover fully and very soon, and there is no need for any investigations like head scan etc.
All the very best!
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