I suspect that you have possibly already lost this job. If they already spoke to you about absence, and you took more time off at such an early stage, I’d be very surprised if they keep you on. Chalk it up to a job that wasn’t meant to be, and look for another.
A couple of things worth remembering. The absences which trigger absence policies, and over all sit poorly with employers, are the odd days here and there. A staff member who has 6months off for surgery, and recovery, or even a week off for flu won’t be as exposed as someone who has one or two days off every other month. The reason for that, is those odd days build a picture of someone who isn’t committed. Even in a small business, if a large proportion of the work force took 3 days off every two months, over a year, the cost to the business would be phenomenal.
The other thing is, your attitude towards your employer. I just get the sense that you’re looking for a way to catch them out. ‘Are they being reasonable?’, ‘should they give me more feedback’, ‘is that bad practice?’.
If as an employee you can put yourself in the employers shoes, imagine how you would feel if the wages you and your colleagues took, came from your pocket. Would you want to be paying Sandra for taking 15 fag breaks a day? would you want to take you on? Knowing little about you, and seeing so many days off? Remember, no one owes you a job. Whether you have heavy periods, migraines, epilepsy, no legs, you are not owed the opportunity to work.
For future reference, you have to work somewhere for 2 years before you can start claiming for unfair/constructive dismissal. With a few exceptions of discrimination.
Good luck.