Hi there... Frequent headache that too during the work hours by mid afternoon is usually due to stress. Childcare is not an easy job as children are full time duty. You might have been taking analgesics for your headache but excess use should be avoided. As in the long rum these painkillers have their side effects mainly on the kidney. There are innumerable causes of headache , if i start listing them . it would be a headache in itself. But most common are the refractive errors of the eye so you should consult an ophthalmologist for a vision test. Other common cause is hypertension, so get your bp recorded. But i would also suggest you to get CT scan of the head to be sure there is nothing pathological as the earlier a problem is known the better it is. You can get yorself examined by a physician personally as he can make out the cause by examination and then advise you appropriate tests needed to confirm the diagnosis.