I have no idea if shes interested it feels like im getting mixed signals?

i like this girl i met about a couple weeks ago. i havent seen her since than because i was on vacation and i just got back last friday and i tried planning a hang out for today but she texted me last night saying she couldnt come today because she said her mom had to get surgery done today and she has to take care of her. she said she feels really really bad :( and it seemed like she was upset the way she texted me and i was like oh np dont worrie take care of your mom and dont feel bad :) and she said so can we move it to this friday and i said yah for sure :) and she said okay :) (when i got back from vacation last friday i went on msn and her friend mentioned a valintines party on the thirteenth and she asked me to go. i said maybee if im not busy. and she said asked me if im going again last night if im going or not and i still dont know :S but i said if im not doing anything ill go :) and i have to go to bed so goodnight :) and she said lmao okay you better be free -_- anyways goodnight =D.) and i have no idea if she likes me :S its hard to say because one random night when i was on vacation she put a heart when i said goodnight with a smile she said goodnight with a heart and that was the only heart i saw from her. im starting to really like her and losing conversation like i dont know what to say anymore i dont want herr to think im boring or ignoring her?