Thanks for using the forum.
Anytime you are having sex, especially unprotected sex, you can get pregnant. Pulling out will not prevent pregnancy because there is sperm present in pre-ejaculate.
Pregnancy occurs when the sperm and egg meet 12-24 hours after ovulation. Ovulation usually occurs mid way through a woman's cycle, or about 13 days after the first day of her last period. With that in mind, if the first day of your last period was July 21, you most likely were not pregnant when you took the tests on the 27th and 30th. If you were to become pregnant it would probably have been during the first few days of August.
Hormone changes can also cause some of the symptoms you mentioned. It can also cause spotting in between periods. If you are experiencing irregularity, and fatigue, you might want to speak with your doctor and make sure that everything is OK.
If you are taking a home pregnancy test, it is important to remember that they are most accurate 1 week after the first day of your last period. A home pregnancy test looks for the presence of the pregnancy hormone hCG. The hormone level has to be high enough to be detected in your urine.
Good luck, I hope that this helps.
That's basically what I'm going threw right now. Except my period got all mixed up. I had bleeding the same time implementation starts. Then a normal period started 28 days from that day.