Guys Im Confused...Pls Help?

My girlfriend went out with her parents yesterday....I had told her before tat if she were goin smwhere to just drop me a msg so as to know where she is....she didnt do tat....so when i called her ard 1 in d afternoon...she msged me sayin tat she's out wit her parents n wld call me back later...so i kept quiet n was waiting 4 her to call back...i msged her at 3 plus..asking where she is...and whether she had her lunch yet? there wasnt any reply..decided to call her at 345.....but she didnt pick up the call....SO i umed that cos she has work at 4 maybe she had reached her workplace n so decided nt 2 disturb her n was waiting 4 her 2 call me back after her work finishes at 10...n den she wld go back n call me...at around 1015p.m.....i logged into msn..n to my horror i saw her online...she said hi to me...i didnt know hw 2 react..i was like huh? how come ur at home..tot u were at work??? how come ur online?? den she told me she didnt go to work today...i was really angry..