Question Summary:
Few weeks ago I saw some blood like spotting once only nothing after that the next day I was all clear and had intercourse. Have I committed a sin?

Question Detail:

 
I gave birth to a baby on the 15th of June after about 30 to 35 days my nifaas finished I had a bath an started to read again. Since then I havent got my periods I believe its because I am excusvily breastfeeding. Few weeks ago I saw some blood like spotting once only nothing after that the next day I was all clear and had intercourse. 
Have I commited gunnah?What kind ? Have I done anything wrong? 
What do I need to do to fix it? 

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
 
Assalāmu ‘alaykum wa rahmatullāhi wa barakātuh
 
If after the day of spotting, you did not notice any bleeding for the following nine days, this would not be considered hayd (menstruation) but istihādah (irregular bleeding). Hence, it was not sinful for you to have had conjugal relations with your husband.
And Allah Ta‘ālā Knows Best
Zameelur Rahman
Student Darul Iftaa
UK
Checked and Approved by,
Mufti Ebrahim Desai.
www.daruliftaa.net