I did not take any pills yet and it is not 24 hours yet. Is there a chance of getting pregnant? IF yes, please suggest me the best birth control pill. My periods are regular with 26 days cycle.

Birth control pills are only effective if they are taken for at least a full month before unprotected sex. And yes while it is possible to get pregnant on your period... because you really do not know when you actually ovulated (don't bother with an app as they are worthless) its not highly likely for many females.

There is no best one, only what's best for you... your OB/GYN will likely have you try several as they all have side effects... some will be worse with some women than with others.

Could you get pregnant, yes. While it is less likely, it is possible.

Birth control pills are as noted, taken daily and would be taken for a month or more prior to sex to be effective. As with patches. There are many forms of birth controls.
You needed to have used a condom. If the man does not want to. Just do not have sex.

There are morning after pills of various names, but they become less and less effective the longer you wait to take them. So you may want to consider going to the local pharmacy and asking for one of the morning after pills. The druggist will explain its use.