Yes, it's very possible.
no no
They count pregnancy from your last menstrual period not from when you actually had sex and conceieved. So if its been 5 wks since you had sex and got pregnant but you had your period like a week before that then you'd be 6 weeks pregnant. Or if you started your period 2 weeks before you had sex then you'd be 7 weeks pregnant.
I'm not entirely sure what you're asking, but if you've had a normal period with normal flow since your last intercourse you are not pregnant.
This is unlikely, although it could be possible depending on when you ovulated.
Menstrual
It depends on what you mean by "safe intercourse." In using any method of birth control there is always a potential of getting pregnant. Nothing is 100% effective except for not having sex. So, yes, there is a possibility that you may be pregnant.
If you have not had your menstrual cycle in three months and this has not happened to you before and you are engaging in sexual intercourse, whether protected or not, there is a great chance you are pregnant.
No. Sperm can only live in the body 5-6 days.
Your menstrual cycle can last a day on some circumstances.Some examples are: if you are stressed, if you have unprotected intercourse it is possible for implantation to occur causing a spotting like period, if you have an irregular period due to overweight,underweight or other factors, sometimes it takes a couple days for your period to start so it may spot for a day in a half till' two days, and some birth control pills will cause you to have breakthru bleeding or spotting.
No. It could be from slight irritation to the cervical area, or from slight tearing at the vaginal opening, or possibly your period was about to start anyway. While this doesn't mean that you are pregnant, it also doesn't mean that you aren't pregnant. If you have been having unprotected sex, and are concerned that you may be pregnant, take a pregnancy test.
I'm not entirely sure where you're going with this question, but if you've had a normal period with normal flow since your last intercourse you are not pregnant.
Just after conception, but usually not until four weeks after the last menstrual period. That is when the "test" turns positive.