Can a girl be pregnant and why hasn't her period came yet?

My girlfriend and I had sex in November and since then we have not had sex. After that we have done few home pregnancy test and one blood pregnancy test at clinic, which all came out negative. However, during the month following she had period with blood clot and not a lot of blood just few stains. And now for the past three months or so she has not have had her period and if she did they are few drops.

My question is can fingering a girl affect her period?

Can she still be pregnant? She does not have big tummy for 6 months pregnancy, it looks normal.

What can be the cause that she has not yet have had her period?

Please help, if there are any doctors and nurses plz let me know. And all those that answer plz list ur professions.

Was she on any kind of birth control previously?Some that contain hormones may cause AMENORRHEA,or abscence of period,OR maybe she's stressing out too much,that can also prevent your period from coming.For sure she is not pregnant but amenorrhea needs to be diagnosed and find the cause,ask her or you can even take her to a clinic,you seem like a nice boyfriend.Fingering does not affect a period at all.If it was her first time back on November then its just the way her body is reacting to this big change.

No fingering shouldnt affect her period. Im sure its just her hormones out of whack, she needs to go to the dr. to get on birth control to regulate her periods.

Do you have a pic of her from like today or not long ago

How old is your girlfriend? I know that a lot of girls/women that have to go on some sort of birth control to regulate their periods. It's very important for her to do so as I believe it can affect her chances of having children in the future.
No, she won't be pregnant from you fingering her. Since it was so long ago and that she has had not only the home pregnancy test but also the blood test, I am pretty sure she is %110 NOT pregnant. The blood tests pick up on the hormone levels in her body indicating if she is pregnant at all. Since they were negative, your girlfriend is not pregnant.
She needs to make an appt. with a clinic or OBGYN to be on some sort of birth control because it is very important that her periods are regulated. They can go into more detail with her there.
Just be careful next time. I am sure this has been a wake up call to both of you. Make sure you are both using some sort of protection. Being a parent is a huge responsibility.

There are many things that can affect a woman's menstrual cycle. From the information you gave, it doesn't sound like she is pregnant, but she needs to be seen by a gynecologist to really know what is causing it. It could potentially be something serious, so the sooner, the better.