info please

Amber

my husband and i have been trying to concieve for awhile. well i just had my period 2 to 21/2 weeks ago. we had sex twice while on my period and everynight since. Tonight i noticed spotting. i never once had spotting in between periods. nor have i ever had 2 periods in onw month. i have had horrible back aches for a couple weeks now and some abdominal pain but nothing unbaring. thjs js just out of my normal. what does it mean.