Very rare
Yes you can.
It could be a cervical change that can cause vaginal bleeding. Vaginal bleeding can also be a symptom of ectopic (tubal) pregnancy. Another cause for bleeding during pregnancy is a miscarriage although the first two reasons for bleeding are more common, it is still a good idea to contact your doctor if you are too concerned.
Signs of pregnancy on the implant are lack of bleeding and positive pregnancy test. Irregular bleeding on the implant is a side effect, and not a sign of pregnancy.
Yes. But second month you can't get it if you are pregnant. :)
Not exactly. Some women have bleeding in the first month of two of pregnancy, but it is not technically a period. Also, if you have heavy bleeding during pregnancy, you might actually be having a miscarriage.
what develelopmeent has taken place in place in the brain by second or third month
Yes. The bleeding can be implantation bleeding, and there are also other 'normal' causes of light bleeding in early pregnancy - the key is that it is 'light' bleeding. Anything heavier could be a menstraul flow, which is not possible during pregnancy. Heavy bleeding during early pregnancy is not okay, and should be checked out immediately. Keep in mind, that sometimes BBT remains high for the first few days of AF, so a high BBT doesn't guarantee pregnancy. However, high BBT for 16 days or more past ovulation with no bleeding is fairly good indication of pregnancy (but still not guaranteed). For example, my luteal phase is 17 days long, and my BBT remains high until 3 days after AF, so many woman might read this 20 day elevation in BBT as pregnancy, when this happens to me naturally every month!
Fetus.
By a medical or surgical abortion. Speak to your doctor.
If you are on birth control then that is normal because it is a side effect. Bleeding between periods can be pregnancy BUT its depends on the person. There are many other reasons why you can be spotting.
bleeding, sometimes pain and cramping. All bleeding cannot be considered an immediate miscarriage. An ultrasound and fetal hearttones need to confirm.