Thanks for your query
Your words suggest that you were having attacks of migraine.Menstruation
is a known triggering factor.I dont know who asked you to take Amoxicillin
.It is a beta lactum antibiotic and is used in Bacterial Infection.It has no role in Migraine.[I hope you are not having sinusitis
for which It can be prescribed].Do not use antibiotics unless doctor advices as it would result in development of bacterial resistance to that antibiotic and it wont be effective in future.Also you will have the side effects of that drug.I again repeat it has no role in migraine.
For those 3-4 days of your migranous attacks you can use NSAIDS like Paracetamol
, 5HT1 receptor agonists like Sumatriptan
.But whatever you take, take it under supervision of your doctor.
Congrats that you are pregnant . Best wishes :)