Brown mucus when using birth control pills - what can it testify?

It is unlikely that taking the contraceptive pill with a 1-hour delay could cause the spotting you write about in the question. You do not mention how long you have been using birth control pills. In the first months of using birth control pills, irregular spotting and bleeding occur relatively often and are not a cause for concern. Spotting with a brown color can sometimes be a sign of an intimate infection. If spotting occurred once and is not accompanied by other ailments, then there is no cause for concern. In the situation described in the question, there are also no concerns about the effectiveness of contraception.