Please advise if it's normal to feel like you have a toothache after you got a filling?

Can be... The process of cleaning out the decay and placing the restoration traumatizes the tooth somewhat. It can take a few days for things to feel normal again. Speak to your restorative dentist for further clarification and guidance.
Maybe. Is it a tooth ache or is it just sensitive. It depends on how deep the restoration was. Is the bite off? Go see the dentist who placed it.
Possibly. A tooth can possibly be sore for a short time after treatment. It is in essence a surgery on the tooth and will need to heal. If the discomfort lasts for awhile, i would have it checked...The bite, etc.