False negative?

[sophiajeffree]

I'm 18 days late. I had my son April 14th and finished my post pregnancy bleeding at 3 weeks. I got a regular menstrual cycle on May 15th. My husband and I have been having fequent unprotected intercourse. I am breast feeding and I know that could delay your mentrual cycle but I already returned to a normal cycle. I began feeling early pregnancy signs including morning sickness. So I took 4 tests in a two week period and they were all negative. Could breast feeding cause  false negatives? Has anyone experienced something similar?

[kaykay2k13]

I also had unprotected sex, but was on birth control to until he turned 6 months old, stopped taking it, still had unprotected sex and didn't get pregnant, it's a lot harder to get pregnant while breastfeeding I've heard, but for some women it may be different.  

[kaykay2k13]

When I breastfeed my son I didn't even have a period.  After having him April 9, 2013 I bleed for two weeks exactly.  Then didn't have one the whole time I breast feed, I didn't get a period until febuary or March this year, after I stopped breathfeesimg for a few weeks.