How early can I know that I my be pregnant? Because I have been feel really weird lately, but I don't know if it just pms? Please help

Most. Most at-home pregnancy tests are fairly accurate a week after your missed period or 5-6 weeks after your last period. Blood and urine pregnancy tests at a doctor's office can detect pregnancy.
Most. Most at-home pregnancy tests are fairly accurate a week after your missed period or 5-6 weeks after your last period. Blood and urine pregnancy tests at a doctor's office can detect pregnancy a little earlier - the blood test can even detect pregnancy 7 days after ovulation (about a week before your period). I attached a link to a web site with more information on how pregnancy tests work and when to take them. Good luck!