Anybody use FF?

Kimberley • TTC 5 years. DS 9, DH & I been married 2 years. Had ectopic lost tube @ 7 wks (2013) on clomid looking to start IVF
I have been charting my bbt since September with FF & and learnt to read when I expect to OV and when AF is due. I took a few months out (clomid) over Xmas due to a chemical pregnancy and restarted end of Jan. Ever since then my bbt chart has been all over the place. I seeked advice from other online forums who mostly told me that bbt was NOT accurate. (It is for me usually) whereas I don't use opks because they simply do not work for me. If anyone could help me out on looking at my chart that'll be great. TIA x