Hi, I Am Female, 24 Years Old. Me And My

Hi,
I am female, 24 years old. Me and my husband are TTC for 3 months. I usually have regular periods and I am almost never late except for this time. I am 4 days late on my periods. I usually have all the PMS symptoms before my period arrives. I have no symptoms this time except for heavy/sore breasts and diarrhea from past 5 days. I am too afraid to take a Home Pregnancy Test because it might say "Negative". How should I know if I am pregnant or if my period arrives.