Why so hard ?

Why is it so hard to get pregnant ? Been trying for 14 months now for #1. I strangely thought that we might of done it this month. Ive been really bad with symptoms. Ive got pains in left and right pelvic area and back which arent comfortable. Ive been haveing dizzy spells, headaches, cold symptoms. Funny taste in my mouth . Breasts are swelling up and now nipples are starting to hurt. The gas has been bad to ( bottom end ) These have been starting since 4DPO and getting worse each day. Im now 8 DPO and ive been getting strong negative pregnancy tests since 7 DPO. Ive never had any of these symptoms before, not even before AF which made me think we have finally done it.... Feeling wiped out 😭😭😭