Is my fiancé pregnant??

My fiance and I have been trying to conceive for the past several months. Her monthly cycle has been irregular since we lost our first child due to incompetent cervix. We spoke with her doctor numerous times, and about 3 months ago he gave her Provera. 
Now, she has been spotting, she has been nausea, and every once in a while some back pains. We have taken 2 test within the last 3 weeks and both showed negative. Just looking for some advice to see what we should do next. Her cycle was suppose to come on Sunday, but as mentioned she just continues to have some spotting at this time.