Gained weight and still no AF!!!!

Well when i went to the DR on the 15th i got weighed and gained 4.5 pounds in 2 weeks really what the hell is going on im so freaking frustrated and to top it of i already new my blood test was negative and my DR called me today to tell me again and said if in ten-fifteen days if dont start AF she wants to give me some pills to start it i really think im pregnant i cant fit my jeans my boobs now fall out of my damn bra and they are already a 34DD i have a belly and people are asking me how far along i am. I know it would be to early to show but im so bloated and gassy it sucks! i cant sleep on my tummy cause it makes me sick in the middle of the night. I am having these night mares that i wake up in a panic crying and have no idea whats going on!!! I have so much discharge my undies feel like i peed but i know i didnt. (sorry if tmi) i have to go to the bathroom twice in an hour. AF will be due in 9 to 10 days the 29th what do i do if it doesnt come?? Me and my husband think im not going to take the pills to start my period cause we really think im pregnant im so regullar that my husband knows what day each month i start and how long AF is. What would you do im so emotional its crazy i think i cry everyday and stupid t.v.!! Would anyone take the pill or just wait and see what happens??? please help!!