My girlfriend (20F) is pregnant and im (22M) suspecting the baby is not mine

Me (22M) and my girlfriend (20F) have been together for 7 months and 1 month ago she took a pregnancy test and it came back positive, So the details are as follows.

  1. She lives in thailand and im form croatia and i went back home october 26 after staying with her for 2 months

  2. On november 5 she sent me a positive pregnancy test

  3. On november 7 she sent me a picture of pretty heavy bleeding from her lady parts

  4. On the november 22 she told me she went to the doctor and he said the fetus was dead fully

  5. I came back to thailand november 28 and had unprotected sex with her the same day and around december 24 a pregnancy test came positive with a very slightly visable line.

  6. On January 21 she got an ultrasound that showed the baby was 8w and 3d old with a size of 18,88 mm

Some other details that might be important: We had sex everyday we stayed together, she was on depo provera 3 month shot from around july 1, the first pregnancy test she sent me was 2 days after a breakup we had because she emotionally cheated and the day she told me the first baby is dead is the same day she told me (2 weeks prior) she would take an ultrasound for me to see the baby because i suspected she faked the pregnancy test. If pictures of the blood or the ultrasound would help find out more details i can dm them,

Basically after talking to my mother we have concluded that something does not add up and she is definitely lying about something. I just want to know what and if the second baby she has right now is even mine?