Thanks for sharing your concern.
Do not worry your dentist
has given you good antibiotic after knowing your past medical records.In my view you must take these antibiotics for three days.
In case you find any allergic changes you can approach your dentist and get the antibiotic changed.
This will help you to minimize the infection caused to you before, during,and after extraction as well as due to oral bacterias.
If not taken care at this stage might give rise to secondary infection and delay healing process.
Therefore you should take an antibiotic course after minor surgical procedure.
After 48 hours, you can start warm saline rinse twice daily, but do remember that you have to rinse slowly without disturbing the clot.
later on you can also use chlorhexidine
mouth wash 2% periodically.Also maintain good oral hygiene
you will be fine soon with this adequate care.
Hope this helps.