Pregnancy scare after ectopic

First off after Monday I have switched doctors. December 14,2017 i did was 7 weeks pregnant and lost my pregnancy was ectopic lost my right tube and also did an d&c; December 22 I went back to the doctor for my check up did pregnancy test and was negative blood work also . i did bleed December 14 to December 20 my doctor told me i could start back having sex and try again I said shouldn't I said she said no my body is open now I should go ahead and try so December 23 we started having unprotected sex. I used preseed and premama upon until January 3.. so I had my second appointment yesterday and it was a different doctor apparently my doctor is out for a few months so I explained to her i had been feeling so nauseous , stomach cramps and after j eat and drink something I start feeling really sick nauseous and dizzy. 3 days before my ob appointment I had ate a sandwich and layed and when I got up I felt so sick and nauseous I felt terrible. so the day of my ob appointment u ate some cereal while in bed and started feeling sick again so I got up. got dressed and driving to my appointment I felt so sick when I got there it just kept feeling like I wanted to throw up. so I did take a pregnancy test and was negative. But again today I was sitting at my table eating and I drank a cup of soda and boom my vagina started cramping and the nausea came back. so my new ob is scared it's been 4 weeks since the surgery and she's scared that I may have gotten pregnant to early and could have a hard pregnancy. My ob was so upset that I didn't wait 3 cycles to try again . But it was not my fault was told wrong information but lately I have been experiencing cramping nausea after eating upper and lower pains vaginal cramps . I'm so upset!! I don't want to lose this next pregnancy. From December 23- January 3 I did takes prenatal vitamins, premama fertility drink and preseed.