Why scam disappear instantly?

I met a girl on russian-dating.com .After few talks there she wanted to move the discussion on yahoo mail. I think you can imagine the talking there...she describe her, what she is doing (live in Enakievo, work as florist, her dad left her family at age 4, her ex left her, etc). Of course she continued with the raising her feelings for me. Every mail had attached 2-3 photos (with her, she and her mom, she and her dog).I asked her to install whatsapp or skype to talk..and guess what...she told me she doesn't have a smart phone, no internet at home..but most of photos were selfie.So i ask her phone number.She gave it to me.I called her and a little strange..she remained surprised.Next weeks i received one e-mail/day except sunday and we talked at phone very day (sometimes 3-4 times/day).I will explain why i called her so often...the e-mail looked strange for me, but on the phone was other person.Interesting that she started to open to me and if in the beggining she told me she have a nice job, she is happy etc..i noticed she is not like that.In one e-mail sent me a photo...let's say a little sexy and asked her about it...she avoid the answer and told me she will tell me when we meet.
In every mail she told me she wants two kids..etc..so i start to ask her when she will do the papers (she told me she doesn't have a passport, plus visa).She answered she is scarried a little about making documents but she will find a solution.Regarding coming here she wanted for me to go first there (to meet in Kiev or Odessa) because what she will do if i will not come?And i explained her i will have to do a invitation for visa so is impossible for me to not come...and also told i will pay her ticket to bus until border to Romania and pick myself from there.All this was happened during almost 4 months.
In one day i asked again about some photos, and i told her she is beautiful.She asked me to not tell this anymore and what i will do if is not her in the photos? So i asked...ok..are you or not there? If not, send me your real photo.She told me: in 10 days you will have a surprise...i am very curios so i asked her again what surprise.Her response: think when we meet and count the days...and you will receive some recent photos.After 10 days she disapperead...change her number, no more message, she deleted the profile on site next day.Reading her last message (one day before she disappeared) i noticed was a normal one, like every day.Even in that day we talked in the morning.
So, what do you think?
PS...sorry for my bad english and long story

i forgot to mention:
i checked some photos...appear just to that site where i met her
IP- associated to Yandex
her e-mail....doesn't appear to other sites
phone number...a pre pay number i think

Its a scam . The profile was probably deleted by the site . There are many romance scammers operating from Russia .

Yes...i thought als is a scammer. It was very strange that her mails looked like classic scams (except some who were normal) but at phone was different almost all the time.What made me to be careful was...fall in love too quick and talking about family with a man she never met and the photos. Every time i asked about them she was stressed (how can have selfie and tell you don't have a smartphone...and she insisted the photos are from 2-3 years..in another one i saw a nice room...asked where is the photo made...in her house before war).
Strange was also she asked me if i am thinking to live in Ukraine...is there the possibility to be a scam, but to start to like me? Or is a tactic for gain my confidence.
If you need i can send mails from her, etc