Hello. Now take a deep breath. Well done for booking yourself a smear test for tomorrow.
Spotting is perfectly normal for a lot of women so calm down. You haven't told us whether you are sexually active or whether you use contraception - and either of those things could exaplain mid cycle spotting, but of course there are plenty of other reasons too!
It's also normal to be a bit itchy down there at the end of your period. It's because the blood becomes dryer at the end of your period and irritates the delicate skin down there on its way out.
Your Dr has only advised you to book a smear test to put your mind at rest, and NOT because you have any cancer symptoms. Also, bear in mind that cervical cancer is VERY EASILY treated if caught early so it's always best to get regular smears.
Good luck for tomorrow hun. You really have nothing to worry about but you're doing the right thing because the test will put your mind at rest. Be brave and let us know how you get on.