The blood that came onto your clothes resulting from your wife's delivery does not affect in any way the validity of your Sawm. Although the blood takes the ruling of Najasah, it is not among the things that invalidate Sawm or nullify Wudu' (ablution). Rather, it should be washed and removed from the body, clothes, and the place of Salah (Prayer). These are among the conditions of the validity of Salah. If you break your Sawm on such a day out of your ignorance, then you are excused and there is no sin incurred on your part, but you must hasten to make up for the missed day of Ramadan and resolve not to do this again. Furthermore, you must ask scholars who are known for their trustworthiness and sound knowledge regarding issues that are unclear to you to be insightful in matters related to your religion and not to commit what contradicts Allah's Shari`ah (Islamic Law).May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.