Period came late two months in a row.i had the same problem last year during this time. rest of the year i have 35 day average cycle. is this concern?

Many options: There are multiple options. Hormonal treatments such as birth control pills, Progesterone treatments and the Mirena (levonorgestrel) iud are effective reversible treatments that will help many people. There is also a drug called Lysteda that contains no hormones which will help others. If this is a one time thing monitoring the next few cycles is reasonable. If it happens alot then consider these