Negative Pregnancy Test

Queanna • I`m 34 yrs old. My husband and I are trying to conceive our second child. We have a 10 yr old son.
So I took my fourth test today and got a BFN! I'm so over stressing myself out! I'm 20 days late and the only thing I notice is I have cramps at the bottom of my stomach. I found out I was pregnant with my son at 8 weeks and only had flu-like symptoms. I'm wondering if this is a repeat of my first pregnancy. My cycles were always weird up until after I had him 10 yrs ago. I'm use to having a period everymonth. I NEED ANSWERS....HELP!!!