Thanks for the query.
No, eating lemon,or ibuprofen
will not delay your cycles. Infact it may cause drug related side effects.
So i do not recommend you to take any of the above to delay your periods.
In order you delay your pills, you can take the active pills (from another pack) for another 3 days.
This can postpone your periods. However do not plan to postpone your periods for more than 3 days.
It could lead to menstrual irregularity later.
Hope this helps,