It is usual to have the breakthrough bleeding
on the first day of new pill.
Breakthrough bleeding or spotting during the first packet of a new pill is not uncommon by any means and the usual advice is to persevere with it and take extra precautions for that month (although the risk of becoming pregnant is extremely low).
It is then usual for such spotting to settle during subsequent packs. However, if you are still experiencing problems by the end of the second month, do discuss this with your gynecologist.
Hope this helps.
Please write back for further queries.
Wishing you good health.