5 1/2 week old baby very congested?

I took my baby to the pediatrician last week because she was very congested. He said it was most likely an unknown allergy and it should resolve itself. Over a week has gone by and she's still very congested. I've been using a bulb syringe to get the snot out a few times a day because it sounds like there is so much snot in her nose, and most times a lot comes out. Someone stated that using the bulb syringe can be dangerous - why is this? They also suggested using saline but my friends son's pediatrician used saline on him in the office and it made him worse, he ended up in the ER so I won't use saline. Is there anything else I can do for her? I plan on calling her doctor Monday if she's still congested like this but what can I do over the weekend?