Suggest Remedy For Delay In Periods

I am 27yrs married women. I had my medication abortion last month june 2014. I started bleeding from 12th june which lasted for 8 10 days. I again did pregnancy test on 23 or 24 june which was negative. I had an unprotected sex wid my husband on 7th july after which on 8th morning I took I pill. I am expecting my periods my 12 july as per 28 days cycle. I am getting worried m I again get Pregnant. Today is 13th july no signs of periods. Pl suggest.