I ovulated 9 days ago, when can I test?

I bought an expensive ovulation tester for home, and tracked my ovulation to the 20th. Me and my husband had on the 16th-21st, because I heard sperm can stay alive for up to 5 days, so I wanted to make sure it took. I am supposed to start my period on the 7th- in 8 days. I took a home pregnancy test first thing this morning and it came back negative, but my are strating to get really sore, and they never do this with the onset of my period, but they were this way when I was pregnant with my first child. Also I am having access milky white discharge, and although I have no spotting, I do have minor pelvic pains. I do not have what you would call morning sickness, but I know that I take care of my elderly grandmother, and usually changing her diapers did not bother me, but I have started gagging over the past few days and have even thrown up twice due to the aggrevation in my stomach afterwards, my stomach gets queezy easily. Do you think I may be pregnant or is it to soon for me to be having some of these issues, also why did the test say negative if I could be pregnant? I am so confused, my little girl is almost 7 years old, so it has been a while since I went through all of this, am I loosing my mind, am I pregnant, or am I making myself think I am pregnant, and if I am pregnant, why did the answer test (more expensive brand), come back negative?