Relationship Doubt: Should I Marry My Girlfriend After Her Long-Term Past?

I had a 2 years relationship with a girl. Last year she left me for another guy and gave him her virginity and got pregnant. After getting abortion that guy left her. Now she came back to me and talked to me for about 2 months just as friends but i loved her so much that i forgave her and accepted her and we got in relationship. But one night she told me about all her past with her 2nd boyfriend. Now i don't want to keep relationship as her past makes me shiver and i promised her for marriage but i can't get over the fact that she cheated me and lost virginity to another guy then came back and wants me to marry her. So if i am not sure of marriage should i involve in physical activities with her ( we never envolved in physical activities before ) or should i avoid doing that until i am sure of marrying her.

I met a girl thought arranged marriage, it's been a 2 week we are talking on vcall and message all day. Abd we like each other a lot. Our thinking match a lot. Sometimes i feel she is understanding me properly and it will be the best relationship for me. She said that she has been 6 to 7 relationship and she was physical with them all along in her past but she will be loyal and devoted to me. Other side I've never been to any kinda relationship in my past and I was focusing on my career and I achive a lot. To be honest I am not able to digest that she was with 7 to 8 guys in proper physical relationship in last 10years. And now she want to settle with me. She is not bringing anything on table other than understanding and look. And I am bringing he'll lot of money, look and understanding. Only thinking killing me is she was with 7 to 8 guys. I didn't meet her yet, we talked a 2 week now family asked to meet an finalize the but look wise I like her but this point is not going away from my mind. I'll be the 9th guy and what she will look after 10th and 11th guy? What should I do?