Uy, preggers sipon is REAL and sobrang annoying, especially pag tulog ka na lang gusto mo pero blocked ka completely! A few of us went through this, one friend swears na humihinga ng mahaba through the mouth lang habang pregnant, at isa naman nag-try ng saline nasal spray from the pharmacy which helped siya. The congestion usually subsides after birth, but since you're only 15 weeks pa, definitely ask your OB what's safe for you to use kasi hindi lahat ng remedies pwede habang buntis, alright?