Scared, aggravated and depressed

Brandy
Hi everyone. I am ttc baby number 4 for 9 months now. I had no problems conceiving my first 2 baby who are now 16 & 14. My 3rd child took me 7 yrs and 3 mc. Im scared because of how long it took me before and that its already been 9 months of ttc. Im not sure i can handle this again. Im aggravated because af was due to visit me june 15 and im always on time. So i thought this could be it. But all the test give me BFN...Im not sure whats going on and that freaks me out... does anyone have any advice???????